Kamiya is in my top five all day.
Fumito Ueda's work changed my whole perspective back in '05 when I played Ico and Shadow back to back; it made me appreciate the way games can make you care so deeply about collections of polygons as if they were real. Emotional, raw, ambitious creations to say the least. The SotC soundtrack may be the best in all games, also.
Tim Schafer is a close second. Adore every game he's touched, pretty much. Grim, Psycho, Day, Monkey, Brutal, Costume, Broken; it's all stellar work with witty, funny writing and lovable characters.
Patrice Désilets. Assassin's Creed II and Sands of Time are two of my favourite games ever, so he has to be in there.