Well, how's Halo 2?
This is the best FPS on xbox to date and the MP is phenominal TONS of online modes and tons of fun.... get this game...Now I know people may like half life 2 more, I am a fan of that series as well, but this game has to be played fully online to be appreciated, I will admit, I have been dissapointed by the offline mode thus far, but the beauty and sheer depth of the online play, hell 16 players online NO LAG.... oh man, is this game sweet, my friend was lucky enough to get it early so I have been playin for like 5 days straight on this, and its awesome, the levels beautiful, the graphics, awesome.. and the dual weapon yielding... tooo fff---in cool... and not to mention, there are alot of fun mp games online.. capture the flag, not it, deathmatch,oddball, the list goes on and on...