Never played xbox

Halo 8)

Doom 3 was fun if you never played the PC version. Only other Xbox game I play on the 360 is Fable, but why play that when you can just get an RPG for the 360

Definitly Ninja gaiden.

THe only other i can think of (if you dont have a PC to play them)

Fable, Half Life 2.

The only otehr thing i can think of is Conker, live and reloaded, if you missed out on the N64 version, becuase its still one of my fav's.