Mainly World of Warcraft, Guild Wars 2 (Once I buy it), Borderlands 2 (Once that comes out), countless source (Valve) games, RIFT, Firefall, and maybe BF3 if it does well in FPS. Right now it's okay but BF3 is just plain bleh on my 560's. It is sorta-okay but not to what I want it.
EDIT: Primarily RIFT, GW2, WoW. Especially RIFT, because I never hit past the 60 FPS mark, and it just goes straight down the tube in high player counts.