Halo
Blood Omen 2 if you like being a bloodsucking bastard
Raw, a SOLID wrestling title, not much of a CAW though
DOA 3, Good fighter with jaw dropping graphics
Maxx Payne, if you don't have it on PC this is the best version
Rallisport Challenge, excellent racing game
JSRF, don't know how to sum it up other than "neato"
Game to Get Soon:
Marrowind: First RPG coming to the XBox and it looks excellent. Comes out at the end of the month.
Brute Force: Tactical FPS coming out this spring SUPPOSEDLY
Legends of Wrestling: Updated parts of the engine that made the PS2 version so forgettable. Plus, you get to be all your favorite wrestling legends from the past. A must if you're a wrestling nut like me.
There are more but I forget right now