There's no softmod for Xbox 360. You either flash as mention above and have to burn dual layer dvds, or rgh to play using hard drives. Both require opening the system and require tools. Flashing is easier. Flashing will make any disc based game work, rgh will make literally any game work.
The only emulators that work really well are Sega Genesis/megadrive and Snes.
Those emulators work great. Even on a 4k TV. The PS1 emulator may be good for some games but eg FFIX lags a little bit. And you dont want a game like that lagging every battle.