Pokemon Blue- I've probably played that game about 20 times, mainly to try out different teams and because I can.
Borderlands- So far 3, and I'm thinking about doing a 4th, that's all with the same character mind you. I will probably do a playthrough with a different character some day, maybe with Mordecai.
God of War: Chains of Olympus- 6 times, just to unlock everything and play the game with different skins, the Scottish one was kinda funny.
Silent Hill 2- I play that game a lot, I would say about 13 times since it came out. I had it first on PC and then when I moved to a Mac I bought a ps2 and bought the game for that.
Diablo 2- Oh god, close to 30 I believe. I wanted to try out different classes and find more loot, and it's also my comfort game, no I don't have a problem!