Seriously, get Halo. Hands down has to be my favorite game on xbox. Plus many people dont really see the huge story inside of the game, but if you really take the time to look at things beyond that, or take the time to read the novels you will see. Good combination of combat, action, weapons, environments, excellent AI, difficulty levels, not to mention highly addictive multiplayer that I still play a lot, either 2 to 16 most of the time. (The multiplayer reminds me of much like goldeneye on n64, in how much I used to play it with my friends). I know people may disagree, but in my opinion one of the greatest games ever made, and one of the best FPS ever made. Like I said thats my opinion.
Also splinter cell. I recomend not to always use a gun for violence more as shooting out lights, etc. And using the element of suprise, and stealth. This is another really great game.
Ghost Recon, is also a very great game, much more squad based, and perfect for xbox live online play.
I have to think of some more, as you listed most of the ones I would have listed too.
Oh and what do you mean by chipped?
![Confuzzled](images/smilies/fuzzleconf.gif)