[Spore]

Team Fortress 2
S.T.A.L.K.E.R.: Shadow of Chernobyl
Left 4 Dead
Garry's Mod
Bioshock
Braid
Call of Duty 4: Modern Warfare
Commander Keen Complete Pack
Counter-Strike: Source
Crysis
Crysis Warhead
Dark Messiah Might and Magic
Darwinia
Doom 2
Doom 3
Doom 3:Resurrection of Evil
Fallout
Fallout 2
Fallout Tactics
Fallout 3
Far Cry
Farcry 2
Final Doom
Half-Life
Half-Life 2
Half-Life 2: Deathmatch
Half-Life 2: Episode 1
Half-Life 2: Episode 2
Half-Life Deathmatch: Source
Half-Life: Blue Shift
Heretic: Shadow of the Serpent Riders
Hexen
Hexen 2
Hexen: Deathkings of the Dark Citadel
I-Fluid
Killing Floor
Lugaru
Master Levels of Doom
Multiwinia
Opposing Force
Peggle Deluxe
Penumbra Black Plague
Portal
Quake
Quake 2
Quake Mission Pack 1: Scourge of Armagon
Quake Mission Pack 2: Dissolution of Eternity
Quake 2: Ground Zero
Quake 2: The Reckoning
Quake 3 Arena
Quake 3 Team Arena
Return to Castle Wolfenstein
Sam and Max Season 1 Episodes 1-4
Serious Sam: Second Encounter
Serious Sam II
The Ship
Spear of Destiny
Star Craft Broodwar
Team Fortress Classic
Unreal Tournament 2004
Unreal Tournament 3
Ultimate Doom
Wolfenstein 3D
Zeno Clash
Black & White
Black & White: Creature Isle
Black & White 2
Spore
The Movies
Unreal Tournament 2003
Battlefield 1942
Thief II
Unreal Gold
Max Payne
Descent: Freespace The Great War
Gish
Penumbra: Haptix
Deus Ex

And some other things

Edit: Minesweeper

More edit: Descent 3
Sims
Sims 2