Wow... I have a lot, but here's a few of my personal faves:
- The obligitory "Pants-on-head Retarded" which, I now actually use in normal conversation
- "Boingo Boingo Whoopsie Knickers!"
- "... A rousing game of bullet kerplunk."
- "Go team retard!"
- "It just goes to show you, never stick your dick in a pudding. It may still be good pudding, and you spend all afternoon explaining that, but no ones going to eat it because you STUCK YOUR DICK IN IT!"
- "... The controls feel stiff and unnatural, and there's a dick joke in there somewhere."
There's plenty more, but I can't even remember most of them.