Seeing as I actually had a lot of fun with Duke Nukem Forever, I think I'm gonna have to go with the YLOD forcing me to replace my PS3.
As far as actual games go, I think the only disappointment that comes to mind is how poorly Bulletstorm's story goes with its gameplay. You walk into a room with savages pinned on spikes, blood everywhere "Oh, what kind of sick bastard would do this?!" says Grayson. ...Erm... You? Like 400 times, five minutes ago. It gives you 100 points and you shouted "Woo, murder party!" immediately after doing it. Thank god for Echo mode.