Devil May Cry 2 - That was a bitter disappoint after the greatness that was DMC1. DMC2 ended up being Devil May Try 2....
Resident Evil 4 - This game does not resemble a RE game. It was a decent standalone game but an absolutely crappy Resident Evil game.
Zelda: Wind Waker - From the Brilliance of Majora's Mask to this joke of a game? LOL Nintendo.
Those are the main ones from me.