Basically the entire script of Kill Bill (blame IsFriday for reminding me), but there's a few in particular I love:
"It's mercy, compassion, and forgiveness I lack. Not rationality." - The Bride
"That woman deserves her revenge, and we deserve to die... but then again, so does she. So I guess we'll see." Bud
"I'm a killer! I'm a murdering bastard, you know that. And there are consequences to breaking the heart of a murdering bastard." - Bill
"No, you're not a bad person. You're a terrific person. You're my favorite person. But every once in a while, you can be a real cunt." - Bill