Left 4 Dead 2 (OMG, this is the game I played the most in my gaming career. 360h since release in November 2009, might not be much to other nerds but still a lot to me)
Arma 2 CO on PVP server (DAO)

R6 Vegas 2 (XBOX 360) in Split Screen Coop with a friend

No CLOD at all