Tekken Tag Tournament 2 - Every other online match where I get pitted against someone that has like 512114124 Wins and 10 Loses to my total of 60 Online matches.
Demon's Souls - After dieing for the umpteenth time in the Valley, I had to take a breather so I wouldn't end up punching my chinchilla.
Prinny - Can I be the Hero? - Every 5 minutes or so.
Knight of the old republic - "Go across the galaxy and find 3 McGuffins to yaddayaddayadda", which reminded me so much of Neverwinter Nights that I had just completed, so I quit it.
Gran Turismo 5 - Losing by 0.005 Seconds on the NASCAR challenge. Fecked it and never went back.
Far Cry 2 - Getting shot at from 20 directions at once without a clue as to where everything is coming from and the radar felt useless. Gave up.