I have been using http://nonmame.retrogames.com/ to decide which emulator to use in retroarch for different systems.
But, for a lot of systems, like gameboy advance or atari 2600 etc it lists Mame as the best choice.
So, I was wondering, I see that I can set Mame up for retroarch for arcade emulation. Is it possible to set it up for gameboy advance or atari 2600 emulation? I don’t see Mame listed for these systems.
Heh, that list is very generous to MESS. You definitely don’t want to use MAME/MESS for GBA. mgba is much, much better and faster. I’m not an atari expert but I believe Stella is a much better option for 2600, as well. I think it also lists MESS as the best option for GBC, which seems … unlikely vs. gambatte.
If we have a core for a system, you can assume it’s probably going to be better (and definitely easier to set up) than MAME/MESS-via-RetroArch. I would recommend trying it and only exploring the MAME/MESS route if you find it to be lacking in some way. NOTE: I can’t speak to the usability of MAME/MESS standalone for that sort of thing but it’s a pain to set up in RetroArch and usually not worth the trouble, IMO.
Thanks for the quick reply! This helps out a lot. Loving retroarch so far! 
I think MAME works good for certain games in RetroArch, because you get to use crt-royale-kurozumi.cgp, which is honestly why I am forced to use it, lol (for a lot of horizontal games). I didn’t have to set anything up other than the shader. Although, I do have to use 0.170 core since the new one is messed up resolution-wise(?)… I’d love to see an improved core that’s a newer version.
EDIT: MESS on the other hand, I hear it’s only good for Atari 5200 or something? Cause that’s the only option.
5200 = Altirra, pretty accurate and constantly updated
Is there a core for this?
There is no RA core for 5200 unless you want to get yourself into the MESS core which is not exactly user friendly to set up. I have setup stand alone MESS for 5200 emulation and it’s a mixed bag. On one hand it isn’t overly difficult to set. Just put your a5200 bios file in the roms folder in mess, put your 5200 roms folder path into the mess.ini and load the game through the command line using the command parameter “a5200 -cart”. Basically the command would look like: mess64.exe a5200 -cart romname
I also use it through the frontend Launchbox which makes it easier. Biggest issue with 5200 emulation through MESS is that in some games the 2nd button just does not want to work. Moon Patrol for example the 2nd button does not jump. Other people over on the Launchbox forums have the exact same problem while the 2nd button works perfectly fine in other games. Another game with issue is Pitfall, it does not recognize pressing the Start button to start playing but Pitfall II works perfectly. Outside of some weird inconsistencies like that it works really well and with HLSL shaders they look really good Altirra and Kat5200 are the only other 5200 emulators I have messed with and both are very good but have quirks in the usability.