My top 50 of all time:
Oblivion
Morrowind
Skyrim
Age of Empires II
Demon's Souls
Dark Souls
Warlords II
Enemy Territory: Quake Wars
Red Dead Redemption
Dark Age of Camelot
Lords of the Realm II
Return to Castle Wolfenstein
Conquests of Camelot
Heretic II
Two Worlds II
Mount & Blade
Warlords
Heretic
Dark Forces
Jedi Knight
Dragon Age: Origins
Gabriel Knight: The Beast Within
Fallout 3
Assassin's Creed II
Dragon's Dogma
Heroes of Might & Magic II
Half-Life 2
Vanquish
Castlevania Lords of Shadow
Assassin's Creed
Bioshock
Dante's Inferno
Battlefield 3
Dead Space
Dark Messiah of Might & Magic
Zelda: Ocarina of Time
God of War 3
Empire Earth
Alan Wake
Tomb Raider
Actually it's a top 40 because I ran out of games that truly deserve to be in a top 50 
And I left out coin-op Arcade games and games from my pre-PC era (Commodore 64 and Amiga).







