GTA IV for its pointless dicking arround value
Halo of your choice and/or COD MW1/2 for there multiplayer
Need for speed: Mostwanted or undercover for fast cars (Burnout is also acceptable)
Borderlands or Fallout 3 for Post-apocoliptic RPG fun
Bioshock/Saintsrow/Assassins creed/Skate for Singleplayer fun times.