My list of Steam Games;
Arma 2: Operation Arrowhead
Battlefield: Bad Company 2
The Binding of Isaac
Borderlands
Brink
Call of Duty 4: Modern Warfare
Call of Duty: Modern Warfare 3
Crysis
Crysis Warhead
Crysis Wars
Dead Space
Dead Space 2
Dirt 3
Dungeon Defenders
The Elder Scrolls IV: Oblivion
Grid
Homefront
Left 4 Dead 2
Limbo
Mass Effect
Mass Effect 2
Metro 2033
Operation Flashpoint: Dragon Rising
Resident Evil 5
Rusty Hearts
Sonic Generations
Spiral Knights
Test Drive Unlimited 2
VVVVVV
War Inc. Battlezone
Waves
The Witcher: Enchanced Edition
That's about it, think of the weekend steam deal but still not sure =D