Battle for Wesnoth (free), Max Payne (1, 2), Oddworld, Psychonauts, Sniper Elite, Battlefront 2, Thief 1 ,2 3, Splinter Cell Chaos Theory, Counter Strike, Doom, Amnesia, Bastion, Breath of Death VII and Chtulu Saves the World, Costume Quest, Dark Messiah, Defense Grid, Gothic, Half-Life 1 and 2, Medieval Total War, Portal, Serious Sam HD, Civilization IV, Sol Survivor, Republic Commando, Audiosurf, Binding of Isaac, Cave Story +, Dungeon Defenders, Jamestown, Mount and Blade (maybe), Super Meat Boy, Terraria, Baldurs Gate 1 and 2, Deus Ex, Morrowind, Oldoblivion, Fallout 1 and 2, Icewind Dale 1 and 2, Magicka, Realm of the Mad God (free), Plants vs Zombies, Freespace, Starcraft, Ultima VII. That's just what I got from my Steam list :/

Im too lazy to link all of them