A lot of good quotes from Fear and Loathing in Las Vegas that I like:
"There I was...Mother of God, there I am!"
"Jesus God!"
"We can't stop here. This is bat country."
Other sources of comedy include Family Guy.
Especially the episode where Brian takes Meg to the prom, and when she asks "How do I look, Brian?" He replies, "You sure do, Meg." If I'm asked a question I don't know or have an answer for, I just reply like that. Someone asked what breed of dog I have (She's a mix of a bunch of stuff) and I said, "She sure is."
From Metal Gear Solid 2:
Raiden: "We've managed to avoid drowning!"
A quote from NC State basketball coach, the late Jim Valvano:
"To me, there are three things we all should do every day. We should do this every day of our lives. Number one is laugh. You should laugh every day. Number two is think. You should spend some time in thought. And Number three is, you should have your emotions moved to tears, could be happiness or joy. But think about it. If you laugh, you think, and you cry, that's a full day. That's a heck of a day. You do that seven days a week, you're going to have something special."
If I think of some more I'll post them, those are just a few favorites.