diff --git a/BizHawk.Client.Common/RomLoader.cs b/BizHawk.Client.Common/RomLoader.cs
index ca46ad5c13..7f02da9f0b 100644
--- a/BizHawk.Client.Common/RomLoader.cs
+++ b/BizHawk.Client.Common/RomLoader.cs
@@ -610,7 +610,7 @@ namespace BizHawk.Client.Common
 
 								var left = Database.GetGameInfo(leftBytes, "left.gb");
 								var right = Database.GetGameInfo(rightBytes, "right.gb");
-								if (Global.Config.GbUseGbHawk)
+								if (Global.Config.PreferredCores["GB"] == CoreNames.GbHawk)
 								{
 									nextEmulator = new GBHawkLink(
 										nextComm,
@@ -960,7 +960,7 @@ namespace BizHawk.Client.Common
 
 							break;
 						case "SNES":
-							bool useSnes9x = Global.Config.SnesInSnes9x;
+							bool useSnes9x = Global.Config.PreferredCores["SNES"] == CoreNames.Snes9X;
 							if (Global.Config.CoreForcingViaGameDb && !string.IsNullOrEmpty(game.ForcedCore))
 							{
 								if (game.ForcedCore.ToLower() == "snes9x")
@@ -991,80 +991,33 @@ namespace BizHawk.Client.Common
 						case "NES":
 						{
 							// apply main spur-of-the-moment switcheroo as lowest priority
-							string preference = "neshawk";
-							if (Global.Config.NesInQuickNes)
-							{
-								preference = "quicknes";
-							}
+							string preference = Global.Config.PreferredCores["NES"];
 
 							// if user has saw fit to override in gamedb, apply that
 							if (Global.Config.CoreForcingViaGameDb && !string.IsNullOrEmpty(game.ForcedCore))
 							{
-								preference = game.ForcedCore;
+								preference = game.ForcedCore.ToLower() switch
+								{
+									"quicknes" => CoreNames.QuickNes,
+									_ => CoreNames.NesHawk
+								};
 							}
 
 							// but only neshawk is accurate
 							if (forceAccurateCore)
 							{
-								preference = "neshawk";
+								preference = CoreNames.NesHawk;
 							}
 
-							if (preference == "neshawk")
-							{
-								core = Global.Config.UseSubNESHawk
-									? CoreInventory.Instance["NES", "SubNESHawk"]
-									: CoreInventory.Instance["NES", "NesHawk"];
-							}
-							else
-							{
-								core = CoreInventory.Instance["NES", "QuickNes"];
-							}
+							core = CoreInventory.Instance["NES", preference];
 						}
-
 							break;
 
 						case "GB":
-							if (!Global.Config.GbAsSgb)
-							{
-								if (Global.Config.UseSubGBHawk)
-								{
-									core = CoreInventory.Instance["GB", "SubGBHawk"];
-								}
-								else
-								{
-									core = Global.Config.GbUseGbHawk
-									? CoreInventory.Instance["GB", "GBHawk"]
-									: CoreInventory.Instance["GB", "Gambatte"];
-								}			
-							}
-							else
-							{
-								if (Global.Config.SgbUseBsnes)
-								{
-									game.System = "SNES";
-									game.AddOption("SGB");
-									var snes = new LibsnesCore(game, rom.FileData, null, null, nextComm, GetCoreSettings<LibsnesCore>(), GetCoreSyncSettings<LibsnesCore>());
-									nextEmulator = snes;
-								}
-								else
-								{
-									core = CoreInventory.Instance["SGB", "SameBoy"];
-								}
-							}
-							break;
 						case "GBC":
 							if (!Global.Config.GbAsSgb)
 							{
-								if (Global.Config.UseSubGBHawk)
-								{
-									core = CoreInventory.Instance["GB", "SubGBHawk"];
-								}
-								else
-								{
-									core = Global.Config.GbUseGbHawk
-									? CoreInventory.Instance["GBC", "GBHawk"]
-									: CoreInventory.Instance["GBC", "Gambatte"];
-								}
+								core = CoreInventory.Instance["GB", Global.Config.PreferredCores["GB"]];
 							}
 							else
 							{
@@ -1106,9 +1059,7 @@ namespace BizHawk.Client.Common
 							nextEmulator = cpc;
 							break;
 						case "GBA":
-							core = Global.Config.GbaUsemGba
-								? CoreInventory.Instance["GBA", "mGBA"]
-								: CoreInventory.Instance["GBA", "VBA-Next"];
+							core = CoreInventory.Instance["GBA", Global.Config.PreferredCores["GBA"]];
 							break;
 						case "PSX":
 							nextEmulator = new Octoshock(nextComm, null, null, rom.FileData, GetCoreSettings<Octoshock>(), GetCoreSyncSettings<Octoshock>(), "PSX etc.");
diff --git a/BizHawk.Client.Common/config/Config.cs b/BizHawk.Client.Common/config/Config.cs
index ea80bac519..17013e7743 100644
--- a/BizHawk.Client.Common/config/Config.cs
+++ b/BizHawk.Client.Common/config/Config.cs
@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.IO;
 using BizHawk.Common;
 using BizHawk.Common.PathExtensions;
+using BizHawk.Emulation.Cores;
 
 namespace BizHawk.Client.Common
 {
@@ -311,16 +312,18 @@ namespace BizHawk.Client.Common
 		// as this setting spans multiple cores and doesn't actually affect the behavior of any core,
 		// it hasn't been absorbed into the new system
 		public bool GbAsSgb { get; set; }
-		public bool UseSubNESHawk { get; set; }
-		public bool UseSubGBHawk { get; set; }
-		public bool NesInQuickNes { get; set; } = true;
-		public bool SnesInSnes9x { get; set; } = true;
-		public bool GbaUsemGba { get; set; } = true;
 		public bool SgbUseBsnes { get; set; }
-		public bool GbUseGbHawk { get; set; }
 		public bool CoreForcingViaGameDb { get; set; } = true;
 		public string LibretroCore { get; set; }
 
+		public Dictionary<string, string> PreferredCores = new Dictionary<string, string>
+		{
+			["NES"] = CoreNames.QuickNes,
+			["SNES"] = CoreNames.Snes9X,
+			["GBA"] = CoreNames.Mgba,
+			["GB"] = CoreNames.Gambatte
+		};
+
 		// ReSharper disable once UnusedMember.Global
 		public string LastWrittenFrom { get; set; } = VersionInfo.MainVersion;
 
diff --git a/BizHawk.Client.Common/movie/MovieSession.cs b/BizHawk.Client.Common/movie/MovieSession.cs
index 1b8782b9b0..dbc25c9550 100644
--- a/BizHawk.Client.Common/movie/MovieSession.cs
+++ b/BizHawk.Client.Common/movie/MovieSession.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 
 using BizHawk.Emulation.Common;
@@ -74,12 +75,7 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		// The behavior here is to only temporarily override these settings when playing a movie and then restore the user's preferred settings
-		// A more elegant approach would be appreciated
-		public bool? PreviousNesInQuickNES { get; set; }
-		public bool? PreviousSnesInSnes9x { get; set; }
-		public bool? PreviousGbaUsemGba { get; set; }
-		public bool? PreviousGbUseGbHawk { get; set; }
+		public IDictionary<string, string> PreferredCores { get; } = new Dictionary<string, string>();
 
 		public void RecreateMovieController(ControllerDefinition definition)
 		{
@@ -258,53 +254,21 @@ namespace BizHawk.Client.Common
 				switch (emulator.SystemId)
 				{
 					case "NES":
-						if (movie.Core == CoreNames.QuickNes)
-						{
-							PreviousNesInQuickNES = Global.Config.NesInQuickNes;
-							Global.Config.NesInQuickNes = true;
-						}
-						else if (movie.Core == CoreNames.NesHawk)
-						{
-							PreviousNesInQuickNES = Global.Config.NesInQuickNes;
-							Global.Config.NesInQuickNes = false;
-						}
+						PreferredCores["NES"] = Global.Config.PreferredCores["NES"];
+						Global.Config.PreferredCores["NES"] = movie.Core;
 						break;
 					case "SNES":
-						if (movie.Core == CoreNames.Snes9X)
-						{
-							PreviousSnesInSnes9x = Global.Config.SnesInSnes9x;
-							Global.Config.SnesInSnes9x = true;
-						}
-						else if (movie.Core == CoreNames.Bsnes)
-						{
-							PreviousSnesInSnes9x = Global.Config.SnesInSnes9x;
-							Global.Config.SnesInSnes9x = false;
-						}
+						PreferredCores["SNES"] = Global.Config.PreferredCores["SNES"];
+						Global.Config.PreferredCores["SNES"] = movie.Core;
 						break;
 					case "GBA":
-						if (movie.Core == CoreNames.Mgba)
-						{
-							PreviousGbaUsemGba = Global.Config.GbaUsemGba;
-							Global.Config.GbaUsemGba = true;
-						}
-						else if (movie.Core == CoreNames.VbaNext)
-						{
-							PreviousGbaUsemGba = Global.Config.GbaUsemGba;
-							Global.Config.GbaUsemGba = false;
-						}
+						PreferredCores["GBA"] = Global.Config.PreferredCores["GBA"];
+						Global.Config.PreferredCores["GBA"] = movie.Core;
 						break;
 					case "GB":
 					case "GBC":
-						if (movie.Core == CoreNames.GbHawk)
-						{
-							PreviousGbUseGbHawk = Global.Config.GbUseGbHawk;
-							Global.Config.GbUseGbHawk = true;
-						}
-						else if (movie.Core == CoreNames.Gambatte)
-						{
-							PreviousGbUseGbHawk = Global.Config.GbUseGbHawk;
-							Global.Config.GbUseGbHawk = false;
-						}
+						PreferredCores["GB"] = Global.Config.PreferredCores["GB"];
+						Global.Config.PreferredCores["GB"] = movie.Core;
 						break;
 				}
 			}
diff --git a/BizHawk.Client.Common/movie/import/LsmvImport.cs b/BizHawk.Client.Common/movie/import/LsmvImport.cs
index 52a3c31eb7..f4d3e1dc37 100644
--- a/BizHawk.Client.Common/movie/import/LsmvImport.cs
+++ b/BizHawk.Client.Common/movie/import/LsmvImport.cs
@@ -5,6 +5,7 @@ using System.Text;
 using BizHawk.Common;
 using BizHawk.Common.IOExtensions;
 using BizHawk.Emulation.Common;
+using BizHawk.Emulation.Cores;
 using BizHawk.Emulation.Cores.Nintendo.SNES;
 
 namespace BizHawk.Client.Common.movie.import
@@ -283,7 +284,7 @@ namespace BizHawk.Client.Common.movie.import
 
 			Result.Movie.HeaderEntries[HeaderKeys.Platform] = platform;
 			Result.Movie.SyncSettingsJson = ConfigService.SaveWithType(ss);
-			Config.SnesInSnes9x = false; // TODO: convert to snes9x if user has set this to true
+			Config.PreferredCores["SNES"] = CoreNames.Bsnes; // TODO: convert to snes9x if it is the user's preference
 		}
 
 		private IController EmptyLmsvFrame()
diff --git a/BizHawk.Client.Common/movie/import/SmvImport.cs b/BizHawk.Client.Common/movie/import/SmvImport.cs
index 935d001e9c..adc2c2a532 100644
--- a/BizHawk.Client.Common/movie/import/SmvImport.cs
+++ b/BizHawk.Client.Common/movie/import/SmvImport.cs
@@ -3,6 +3,7 @@ using System.IO;
 using System.Linq;
 using System.Text;
 using BizHawk.Emulation.Common;
+using BizHawk.Emulation.Cores;
 using BizHawk.Emulation.Cores.Nintendo.SNES;
 
 namespace BizHawk.Client.Common.movie.import
@@ -313,7 +314,7 @@ namespace BizHawk.Client.Common.movie.import
 				Result.Movie.AppendFrame(controllers);
 
 				Result.Movie.SyncSettingsJson = ConfigService.SaveWithType(ss);
-				Config.SnesInSnes9x = false; // TODO: convert to snes9x if user has set this to true
+				Config.PreferredCores["SNES"] = CoreNames.Bsnes; // TODO: convert to snes9x if it is the user's preference
 			}
 		}
 	}
diff --git a/BizHawk.Client.Common/movie/import/VbmImport.cs b/BizHawk.Client.Common/movie/import/VbmImport.cs
index 405dd208da..278e17b771 100644
--- a/BizHawk.Client.Common/movie/import/VbmImport.cs
+++ b/BizHawk.Client.Common/movie/import/VbmImport.cs
@@ -1,6 +1,7 @@
 using System;
 using System.IO;
 using BizHawk.Emulation.Common;
+using BizHawk.Emulation.Cores;
 using BizHawk.Emulation.Cores.Nintendo.GBA;
 using BizHawk.Emulation.Cores.Nintendo.GBHawk;
 using BizHawk.Emulation.Cores.Nintendo.Gameboy;
@@ -274,13 +275,13 @@ namespace BizHawk.Client.Common.movie.import
 
 			if (isGBA)
 			{
-				Config.GbaUsemGba = true;
+				Config.PreferredCores["GBA"] = CoreNames.Mgba;
 				var ss = new MGBAHawk.SyncSettings { SkipBios = true };
 				Result.Movie.SyncSettingsJson = ConfigService.SaveWithType(ss);
 			}
 			else
 			{
-				if (Config.GbUseGbHawk || Config.UseSubGBHawk)
+				if (Config.PreferredCores["GB"] == CoreNames.GbHawk || Config.PreferredCores["GB"] == CoreNames.SubGbHawk)
 				{
 					var tempSync = new GBHawk.GBSyncSettings();
 					if (is_GBC) { tempSync.ConsoleMode = GBHawk.GBSyncSettings.ConsoleModeType.GBC; }
diff --git a/BizHawk.Client.Common/movie/interfaces/IMovieSession.cs b/BizHawk.Client.Common/movie/interfaces/IMovieSession.cs
index 6c1b12094a..2157b2b55c 100644
--- a/BizHawk.Client.Common/movie/interfaces/IMovieSession.cs
+++ b/BizHawk.Client.Common/movie/interfaces/IMovieSession.cs
@@ -1,4 +1,5 @@
-using System.IO;
+using System.Collections.Generic;
+using System.IO;
 using BizHawk.Emulation.Common;
 
 namespace BizHawk.Client.Common
@@ -28,11 +29,10 @@ namespace BizHawk.Client.Common
 
 		IController PreviousFrame { get; }
 
-		// TODO: this isn't sustainable
-		bool? PreviousNesInQuickNES { get; set; }
-		bool? PreviousSnesInSnes9x { get; set; }
-		bool? PreviousGbaUsemGba { get; set; }
-		bool? PreviousGbUseGbHawk { get; set; }
+		/// <summary>
+		/// Previous saved core preferences. Stored so that they can be stored after a movie overrides the value
+		/// </summary>
+		IDictionary<string, string> PreferredCores { get; }
 
 		/// <summary>
 		/// Recreates MovieController with the given controller definition
diff --git a/BizHawk.Client.EmuHawk/EmuHawkUtil.cs b/BizHawk.Client.EmuHawk/EmuHawkUtil.cs
index a291266b2d..60d2e01b51 100644
--- a/BizHawk.Client.EmuHawk/EmuHawkUtil.cs
+++ b/BizHawk.Client.EmuHawk/EmuHawkUtil.cs
@@ -45,8 +45,8 @@ namespace BizHawk.Client.EmuHawk
 
 			return emulator switch
 			{
-				Snes9x _ => PromptToSwitchCore("Snes9x", "bsnes", () => Global.Config.SnesInSnes9x = false),
-				QuickNES _ => PromptToSwitchCore("QuickNes", "NesHawk", () => Global.Config.NesInQuickNes = false),
+				Snes9x _ => PromptToSwitchCore("Snes9x", "bsnes", () => Global.Config.PreferredCores["SNES"] = Cores.CoreNames.Bsnes),
+				QuickNES _ => PromptToSwitchCore("QuickNes", "NesHawk", () => Global.Config.PreferredCores["NES"] = Cores.CoreNames.QuickNes),
 				_ => true
 			};
 		}
diff --git a/BizHawk.Client.EmuHawk/MainForm.Designer.cs b/BizHawk.Client.EmuHawk/MainForm.Designer.cs
index 952244bf6e..b28218c7c0 100644
--- a/BizHawk.Client.EmuHawk/MainForm.Designer.cs
+++ b/BizHawk.Client.EmuHawk/MainForm.Designer.cs
@@ -1949,7 +1949,7 @@
 			this.GBGambatteMenuItem.Name = "GBGambatteMenuItem";
 			this.GBGambatteMenuItem.Size = new System.Drawing.Size(121, 22);
 			this.GBGambatteMenuItem.Text = "Gambatte";
-			this.GBGambatteMenuItem.Click += new System.EventHandler(this.GBCorePick_Click);
+			this.GBGambatteMenuItem.Click += new System.EventHandler(this.GambatteCorePick_Click);
 			// 
 			// GBGBHawkMenuItem
 			// 
diff --git a/BizHawk.Client.EmuHawk/MainForm.Events.cs b/BizHawk.Client.EmuHawk/MainForm.Events.cs
index cbe876fb0b..ddce19eb76 100644
--- a/BizHawk.Client.EmuHawk/MainForm.Events.cs
+++ b/BizHawk.Client.EmuHawk/MainForm.Events.cs
@@ -19,6 +19,7 @@ using BizHawk.Client.EmuHawk.ToolExtensions;
 using BizHawk.Emulation.Cores.Computers.AppleII;
 using BizHawk.Common;
 using BizHawk.Common.PathExtensions;
+using BizHawk.Emulation.Cores;
 using BizHawk.Emulation.Cores.Atari.A7800Hawk;
 using BizHawk.Emulation.Cores.Computers.Commodore64;
 using BizHawk.Emulation.Cores.Nintendo.Gameboy;
@@ -936,8 +937,8 @@ namespace BizHawk.Client.EmuHawk
 
 		private void CoreMenuItem_DropDownOpened(object sender, EventArgs e)
 		{
-			quickNESMenuItem.Checked = Config.NesInQuickNes;
-			nesHawkMenuItem.Checked = !Config.NesInQuickNes;
+			quickNESMenuItem.Checked = Config.PreferredCores["NES"] == CoreNames.QuickNes;
+			nesHawkMenuItem.Checked = Config.PreferredCores["NES"] == CoreNames.NesHawk;
 		}
 
 		private void ControllersMenuItem_Click(object sender, EventArgs e)
@@ -1199,15 +1200,14 @@ namespace BizHawk.Client.EmuHawk
 
 		private void NesCoreSubMenu_DropDownOpened(object sender, EventArgs e)
 		{
-			QuicknesCoreMenuItem.Checked = Config.NesInQuickNes;
-			NesCoreMenuItem.Checked = !Config.NesInQuickNes && !Config.UseSubNESHawk;
-			SubNesHawkMenuItem.Checked = Config.UseSubNESHawk;
+			QuicknesCoreMenuItem.Checked = Config.PreferredCores["NES"] == CoreNames.QuickNes;
+			NesCoreMenuItem.Checked = Config.PreferredCores["NES"] == CoreNames.NesHawk;
+			SubNesHawkMenuItem.Checked = Config.PreferredCores["NES"] == CoreNames.SubNesHawk;
 		}
 
 		private void QuickNesCorePick_Click(object sender, EventArgs e)
 		{
-			Config.NesInQuickNes = true;
-			Config.UseSubNESHawk = false;
+			Config.PreferredCores["NES"] = CoreNames.QuickNes;
 
 			if (Emulator.SystemId == "NES")
 			{
@@ -1217,8 +1217,7 @@ namespace BizHawk.Client.EmuHawk
 
 		private void NesCorePick_Click(object sender, EventArgs e)
 		{
-			Config.NesInQuickNes = false;
-			Config.UseSubNESHawk = false;
+			Config.PreferredCores["NES"] = CoreNames.NesHawk;
 
 			if (Emulator.SystemId == "NES")
 			{
@@ -1228,20 +1227,9 @@ namespace BizHawk.Client.EmuHawk
 
 		private void SubNesCorePick_Click(object sender, EventArgs e)
 		{
-			Config.UseSubNESHawk = true;
-			Config.NesInQuickNes = false;
+			Config.PreferredCores["NES"] = CoreNames.SubNesHawk;
 
-			if (!Emulator.IsNull())
-			{
-				FlagNeedsReboot();
-			}
-		}
-
-		private void SubGBCorePick_Click(object sender, EventArgs e)
-		{
-			Config.UseSubGBHawk ^= true;
-
-			if (!Emulator.IsNull())
+			if (Emulator.SystemId == "NES")
 			{
 				FlagNeedsReboot();
 			}
@@ -1249,13 +1237,15 @@ namespace BizHawk.Client.EmuHawk
 
 		private void CoreSNESSubMenu_DropDownOpened(object sender, EventArgs e)
 		{
-			Coresnes9xMenuItem.Checked = Config.SnesInSnes9x;
-			CorebsnesMenuItem.Checked = !Config.SnesInSnes9x;
+			Coresnes9xMenuItem.Checked = Config.PreferredCores["SNES"] == CoreNames.Snes9X;
+			CorebsnesMenuItem.Checked = Config.PreferredCores["SNES"] == CoreNames.Bsnes;
 		}
 
 		private void CoreSnesToggle_Click(object sender, EventArgs e)
 		{
-			Config.SnesInSnes9x ^= true;
+			Config.PreferredCores["SNES"] = Config.PreferredCores["SNES"] == CoreNames.Snes9X
+				? CoreNames.Bsnes
+				: CoreNames.Snes9X;
 
 			if (Emulator.SystemId == "SNES")
 			{
@@ -1265,13 +1255,15 @@ namespace BizHawk.Client.EmuHawk
 
 		private void GbaCoreSubMenu_DropDownOpened(object sender, EventArgs e)
 		{
-			VbaNextCoreMenuItem.Checked = !Config.GbaUsemGba;
-			MgbaCoreMenuItem.Checked = Config.GbaUsemGba;
+			VbaNextCoreMenuItem.Checked = Config.PreferredCores["GBA"] == CoreNames.VbaNext;
+			MgbaCoreMenuItem.Checked = Config.PreferredCores["GBA"] == CoreNames.Mgba;
 		}
 
 		private void GbaCorePick_Click(object sender, EventArgs e)
 		{
-			Config.GbaUsemGba ^= true;
+			Config.PreferredCores["GBA"] = Config.PreferredCores["GBA"] == CoreNames.VbaNext
+				? CoreNames.Mgba
+				: CoreNames.VbaNext;
 			if (Emulator.SystemId == "GBA")
 			{
 				FlagNeedsReboot();
@@ -1286,16 +1278,34 @@ namespace BizHawk.Client.EmuHawk
 
 		private void GBCoreSubmenu_DropDownOpened(object sender, EventArgs e)
 		{
-			GBGambatteMenuItem.Checked = !Config.GbUseGbHawk;
-			GBGBHawkMenuItem.Checked = Config.GbUseGbHawk;
-			SubGBHawkMenuItem.Checked = Config.UseSubGBHawk;
+			GBGambatteMenuItem.Checked = Config.PreferredCores["GB"] == CoreNames.Gambatte;
+			GBGBHawkMenuItem.Checked = Config.PreferredCores["GB"] == CoreNames.GbHawk;
+			SubGBHawkMenuItem.Checked = Config.PreferredCores["GB"] == CoreNames.SubGbHawk;
+		}
+
+		private void SubGBCorePick_Click(object sender, EventArgs e)
+		{
+			Config.PreferredCores["GB"] = CoreNames.SubGbHawk;
+			if (Emulator.SystemId == "GB" || Emulator.SystemId == "GBC")
+			{
+				FlagNeedsReboot();
+			}
 		}
 
 		private void SgbCorePick_Click(object sender, EventArgs e)
 		{
 			Config.SgbUseBsnes ^= true;
-			// TODO: only flag if one of these cores
-			if (!Emulator.IsNull())
+			if (Emulator.SystemId == "GB" || Emulator.SystemId == "GBC")
+			{
+				FlagNeedsReboot();
+			}
+		}
+
+		private void GambatteCorePick_Click(object sender, EventArgs e)
+		{
+			Config.PreferredCores["GB"] = CoreNames.Gambatte;
+
+			if (Emulator.SystemId == "GB" || Emulator.SystemId == "GBC")
 			{
 				FlagNeedsReboot();
 			}
@@ -1303,10 +1313,9 @@ namespace BizHawk.Client.EmuHawk
 
 		private void GBCorePick_Click(object sender, EventArgs e)
 		{
-			Config.GbUseGbHawk ^= true;
-			Config.UseSubGBHawk = false;
-			// TODO: only flag if one of these cores
-			if (!Emulator.IsNull())
+			Config.PreferredCores["GB"] = CoreNames.GbHawk;
+
+			if (Emulator.SystemId == "GB" || Emulator.SystemId == "GBC")
 			{
 				FlagNeedsReboot();
 			}
@@ -1550,13 +1559,13 @@ namespace BizHawk.Client.EmuHawk
 
 		private void QuickNesMenuItem_Click(object sender, EventArgs e)
 		{
-			Config.NesInQuickNes = true;
+			Config.PreferredCores["NES"] = CoreNames.QuickNes;
 			FlagNeedsReboot();
 		}
 
 		private void NesHawkMenuItem_Click(object sender, EventArgs e)
 		{
-			Config.NesInQuickNes = false;
+			Config.PreferredCores["NES"] = CoreNames.NesHawk;
 			FlagNeedsReboot();
 		}
 
@@ -2006,13 +2015,13 @@ namespace BizHawk.Client.EmuHawk
 
 		private void UsemGBAMenuItem_Click(object sender, EventArgs e)
 		{
-			Config.GbaUsemGba = true;
+			Config.PreferredCores["GBA"] = CoreNames.Mgba;
 			FlagNeedsReboot();
 		}
 
 		private void UseVbaNextMenuItem_Click(object sender, EventArgs e)
 		{
-			Config.GbaUsemGba = false;
+			Config.PreferredCores["GBA"] = CoreNames.VbaNext;
 			FlagNeedsReboot();
 		}
 
@@ -2023,8 +2032,8 @@ namespace BizHawk.Client.EmuHawk
 
 		private void GBACoreSelectionSubMenu_DropDownOpened(object sender, EventArgs e)
 		{
-			GBAmGBAMenuItem.Checked = Config.GbaUsemGba;
-			GBAVBANextMenuItem.Checked = !Config.GbaUsemGba;
+			GBAmGBAMenuItem.Checked = Config.PreferredCores["GBA"] == CoreNames.Mgba;
+			GBAVBANextMenuItem.Checked = Config.PreferredCores["GBA"] == CoreNames.VbaNext;
 		}
 
 		#endregion
diff --git a/BizHawk.Client.EmuHawk/MainForm.Movie.cs b/BizHawk.Client.EmuHawk/MainForm.Movie.cs
index 5e3fa3d985..7276311c43 100644
--- a/BizHawk.Client.EmuHawk/MainForm.Movie.cs
+++ b/BizHawk.Client.EmuHawk/MainForm.Movie.cs
@@ -31,28 +31,9 @@ namespace BizHawk.Client.EmuHawk
 
 			RebootCore();
 
-			if (MovieSession.PreviousNesInQuickNES.HasValue)
+			foreach (var previousPref in MovieSession.PreferredCores)
 			{
-				Config.NesInQuickNes = MovieSession.PreviousNesInQuickNES.Value;
-				MovieSession.PreviousNesInQuickNES = null;
-			}
-
-			if (MovieSession.PreviousSnesInSnes9x.HasValue)
-			{
-				Config.SnesInSnes9x = MovieSession.PreviousSnesInSnes9x.Value;
-				MovieSession.PreviousSnesInSnes9x = null;
-			}
-
-			if (MovieSession.PreviousGbaUsemGba.HasValue)
-			{
-				Config.GbaUsemGba = MovieSession.PreviousGbaUsemGba.Value;
-				MovieSession.PreviousGbaUsemGba = null;
-			}
-
-			if (MovieSession.PreviousGbUseGbHawk.HasValue)
-			{
-				Config.GbUseGbHawk = MovieSession.PreviousGbUseGbHawk.Value;
-				MovieSession.PreviousGbUseGbHawk = null;
+				Config.PreferredCores[previousPref.Key] = previousPref.Value;
 			}
 
 			Config.RecentMovies.Add(movie.Filename);
diff --git a/BizHawk.Client.EmuHawk/config/ProfileConfig.cs b/BizHawk.Client.EmuHawk/config/ProfileConfig.cs
index 30584a5800..e70fc9c0b0 100644
--- a/BizHawk.Client.EmuHawk/config/ProfileConfig.cs
+++ b/BizHawk.Client.EmuHawk/config/ProfileConfig.cs
@@ -3,7 +3,7 @@ using System.Windows.Forms;
 
 using BizHawk.Client.Common;
 using BizHawk.Emulation.Common;
-
+using BizHawk.Emulation.Cores;
 using BizHawk.Emulation.Cores.Nintendo.N64;
 using BizHawk.Emulation.Cores.Consoles.Sega.gpgx;
 using BizHawk.Emulation.Cores.Sega.MasterSystem;
@@ -113,7 +113,7 @@ namespace BizHawk.Client.EmuHawk
 			PutSyncSettings<N64>(n64Settings);
 
 			// SNES
-			_config.SnesInSnes9x = true;
+			_config.PreferredCores["SNES"] = CoreNames.Snes9X;
 
 			// Genesis
 			var genesisSettings = GetSyncSettings<GPGX, GPGX.GPGXSyncSettings>();
@@ -138,7 +138,7 @@ namespace BizHawk.Client.EmuHawk
 			PutSyncSettings<Atari2600>(a2600Settings);
 
 			// NES
-			_config.NesInQuickNes = true;
+			_config.PreferredCores["NES"] = CoreNames.QuickNes;
 		}
 
 		private void SetLongPlay()
@@ -146,7 +146,7 @@ namespace BizHawk.Client.EmuHawk
 			_config.SaveStateCompressionLevelNormal = 5;
 
 			// SNES
-			_config.SnesInSnes9x = false;
+			_config.PreferredCores["SNES"] = CoreNames.Bsnes;
 
 			// SMS
 			var smsSettings = GetSyncSettings<SMS, SMS.SmsSyncSettings>();
@@ -161,7 +161,7 @@ namespace BizHawk.Client.EmuHawk
 			PutSyncSettings<Atari2600>(a2600Settings);
 
 			// NES
-			_config.NesInQuickNes = false;
+			_config.PreferredCores["NES"] = CoreNames.NesHawk;
 		}
 
 		private void SetTas()
@@ -185,7 +185,7 @@ namespace BizHawk.Client.EmuHawk
 			PutSyncSettings<N64>(n64Settings);
 
 			// SNES
-			_config.SnesInSnes9x = false;
+			_config.PreferredCores["SNES"] = CoreNames.Snes9X;
 
 			// Genesis
 			var genesisSettings = GetSyncSettings<GPGX, GPGX.GPGXSyncSettings>();
@@ -205,7 +205,7 @@ namespace BizHawk.Client.EmuHawk
 			PutSyncSettings<Atari2600>(a2600Settings);
 
 			// NES
-			_config.NesInQuickNes = false;
+			_config.PreferredCores["NES"] = CoreNames.NesHawk;
 		}
 
 		private void SetN64Tas()
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBA/VBANext.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBA/VBANext.cs
index 65a96b83ec..26512fcab0 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBA/VBANext.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBA/VBANext.cs
@@ -7,7 +7,7 @@ using BizHawk.Emulation.Cores.Components.ARM;
 
 namespace BizHawk.Emulation.Cores.Nintendo.GBA
 {
-	[Core("VBA-Next", "many authors", true, true, "cd508312a29ed8c29dacac1b11c2dce56c338a54", "https://github.com/libretro/vba-next", false)]
+	[Core(CoreNames.VbaNext, "many authors", true, true, "cd508312a29ed8c29dacac1b11c2dce56c338a54", "https://github.com/libretro/vba-next", false)]
 	[ServiceNotApplicable(new[] { typeof(IDriveLight), typeof(IRegionable) })]
 	public partial class VBANext : IEmulator, IVideoProvider, ISoundProvider, IInputPollable,
 		IGBAGPUViewable, ISaveRam, IStatable, IDebuggable, ISettable<object, VBANext.SyncSettings>
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/SubGBHawk/SubGBHawk.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/SubGBHawk/SubGBHawk.cs
index d325f61c3d..94617ad8dd 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/SubGBHawk/SubGBHawk.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/SubGBHawk/SubGBHawk.cs
@@ -1,10 +1,9 @@
 using BizHawk.Emulation.Common;
-using BizHawk.Emulation.Cores.Nintendo.GBHawk;
 
 namespace BizHawk.Emulation.Cores.Nintendo.SubGBHawk
 {
 	[Core(
-		"SubGBHawk",
+		CoreNames.SubGbHawk,
 		"",
 		isPorted: false,
 		isReleased: true)]
diff --git a/BizHawk.Emulation.Cores/CoreNames.cs b/BizHawk.Emulation.Cores/CoreNames.cs
index e873d71efe..fc2dfbbc86 100644
--- a/BizHawk.Emulation.Cores/CoreNames.cs
+++ b/BizHawk.Emulation.Cores/CoreNames.cs
@@ -18,5 +18,6 @@ namespace BizHawk.Emulation.Cores
 		public const string VbaNext = "VBA-Next";
 		public const string GbHawk = "GBHawk";
 		public const string Gambatte = "Gambatte";
+		public const string SubGbHawk = "SubGBHawk";
 	}
 }