Far Cry: its dated, but awesome! Made by Crytek.
Far Cry 2: not sure you will like it, you will have to research on it a bit. Made by Ubisoft.
Crysis Warhead: expansion of the Crysis game, made by Crytek Budapest.
Battlefield: Bad Company 2: great game for the multiplayer, if you like tactical gameplay. The singleplayer was horrible in my opinion. Made by DICE.
Call of Duty: Modern Warfare 2: I suggest you avoid this game at all costs! Buy it on a console if you get it at all.
Counterstrike: Source: great game to get your aim and trigger finger seasoned to perfection.
Battlefield 2: great tactical game, dated, but awesome! 64 players, aircraft, tanks, the whole shibang.
Battlefield 2142: similar to the other BF games, but set in the future.
That's about it!