What is the best computer game in the world

There is no real right or wrong answer here. This is a question asking for anyone's personal opinion:

Super Tux
RuneScape
Civilization IV
Planescape: Torment
GTA 4
Hitman : Blood money
Assassin's Creed
Halo
Serious SAM
Fable 1
Bio-Shock 2
World of Warcraft
Zoo tycoon
Far Cry 2