Emulation on the Xbox 360!
Not as developed as in other platforms but after little tinkering got a ton of games to run great, got the emus from the aurora homebrew store script and from here: https://consolemods.org/wiki/Xbox\_360:Emulators
Showcasing what I think are the best emus from my testing: RetroArch, standalone Retroarch cores (nestopia, genesis plus, vba, gambatte), FBNeo, Snes 360 enhanced and PCSXR 360.
Some tips and tricks I learned:
A bunch of the emus won't install from the homebrew store to a Xbox 360 internal hard drive as the names of some of the files inside the emus are too long or have symbols and other characters, installing them to an external usb or hard drive works fine though, same applies to roms names.
In RetroArch go to video settings and set aspect ratio to core provided and integer scaling to on for pixel perfect retro games, other standalone emus options for resizing the screen are very limited.
If a standalone RetroArch core doesn't have a cover in Aurora, press Y on it and rename it to just RetroArch then select download cover and a bunch of covers will now show, after selecting one you can rename again to whatever you want.
The full RetroArch 1.0.0.2 and the Retroarch standalone cores have a slightly different UI and confirmation buttons, in Retroarch the confirmation button is B in the Xbox 360 controller and A is back, in the standalone cores the reverse is the case. Also the standalone cores have an extra menu option when running a core to remap the buttons without having to remap the whole gamepad in input settings, though some of the standalone cores don't work at all like the MAME and the neogeo pocket ones but those same cores do work in the full RetroArch emu. Also in-game colors are a bit different between the full RetroArch and the Retroarch standalone cores for some reason.
To open the RetroArch GUI when running a game press both sticks, if using the standalone cores you only have to press on the left stick.
For arcade and snes games the standalone emus FBNeo and Snes 360 enhanced worked the best for me and both have easy options to change aspect ratio and screensize, apply filters, save states, remap controllers etc.
For ps1 games the emu PCSXR 360 is the only one that works afaik and you can select the .bin roms from any path and device unlike the other emus where you have to place the roms in the emu specific roms folder, but sadly game compatibility is limited, you also can not change the aspect ratio so all games will look stretched at 16:9, also no controller remapping, options are limited but you can open them ingame by pressing all the face buttons, the front buttons and the triggers.
For nes games used the nestopia standalone Retroarch core and not Fce360 as nestopia has core options for filters and to remove the sprites limit flickering.
Overall had a lot of fun but still wishing RetroArch would get updated to a more recent version now that a bad avatar makes emus installable on any Xbox 360, seems some of the devs have expressed interest in updating it too so there is still hope.