(In XPO) Awesome-X: "And the villabouts of the wherein Kelly."
Xtacle: "Whereabouts of the villain Killface."
Awesome X: "Did I say the villabouts of the wherein Kelly?"
Xtacle: "Yeah."
Awesome X: "'Cause I've been doing that a lot lately. I wonder if it's a tumor."
(The Middle) Sinn as Hooper: And then gear up, because we are going to assasinate the wherein Kelly.
Xtacle: Uh, the villian Killface.
(XPO) Stan: You can't fax glitter.
Xander: Well, not with that attitude.
(The Debate, Part One) (off camera guy): "Hawk,I think you slipped in an extra Carter Hawkins."
CH: "Who is that who says that? Come on who always says it?"
(off camera guy): "My **BLEEP** Mom."
CH: "Ha-huga!"
(Meet Antagone) Xander: "Hey-Hey-Hey! That's Awesome X you're caressing!"
(The Debate, Part One) Xander: "Aah, my arm **BLEEP**!"
(The Debate, Part One) Xtacles: 1."I FIND FAULT WITH THAT IMAGERY!" Xtacle 2: ME TOO!"
Xtacle 3 (referring to grape soda): "WHAT IS THIS, LIQUID ANGER?!"
(The Debate, Two) Limo driver: "**BLEEP**ing Penguins."
(The Opposition) Wendell: "Cheese and rice, he shot himself -- with my gun somehow!"
(The Image Problem)Xander: "Uh...spit take?!"
(The Issues) Killface: "I know, I know; But I just can't stay mad at him."
Grace Ryan: 1. "I know. I just can't stay mad at him." 2. "God, still can't stay mad at him!"
(The Debate, Part Two) Killface to Simon: "No, you can't has cheeseburger."
Xander to pregnant Grace Ryan: "Uh, no, you can't has cheeseburgers, you big fatty. Why are you so fat?"
(I actually restrained myself, there are so many quotables. Also loving many of the quotes already posted by others. Especially Killface's favorite exclamation.)
Don't continue banging your head against the wall, just because it feels good when you stop.