My personal favorites:

Dave's date: uhm, the craziest thing i ever did sexually, ok, one time i had a three way with these two guys in college and my sorority sisters were cheering me on"
Dave Chappelle: Craziest thing i ever did sexually(pauses), probably having sex with old gang bang here without a rubber. we're fricking done man. this date is over.

Katie Jacobson: You want me to light your cigarette for you too?
Leonard Washington: You better check ya tone girl, put ya inside voice on. 'Fore I put ya arse outside!

"Bitch wears drawers with dick holes in them"

Businessman: I'll have a Samuel Jackson.
Samuel Jackson: [shouts] Good motherfricking choice, motherfricker! Samuel Jackson! Made painstakingly by me, Samuel L. Jackson! It'll get ya drunk! You'll be fricking fat girls in no time! You might even fight a **** or two! Mmmm-mmm, bitch!
[Jackson walks up to the businessman]
Samuel Jackson: [shouts] How's it taste, motherfricker?
Businessman: Could you please stop yelling at me?
Samuel Jackson: [shouts] No, I can't stop yelling, 'cause that's how I talk! Haven't you seen my movies? "Juice" That was a good one! "Deep Blue Sea" They ate me! A motherfricking shark ate me! Drink up, bitch!

Clayton Bigsby: Let's talk about Chinese people! With their kung-fu and their silly chang-chang-chong talk! We can't understand you! Go back to yer country! White power!

Prosecutor: You know, he's been accused of this before.
Dave Chappelle: So? Some people say the cucumbers taste better pickled.
Prosecutor: What?
Dave Chappelle: Huh?
Prosecutor: What?
Dave Chappelle: Huh?
Prosecutor: So, you don't think Michael Jackson is guilty?
Dave Chappelle: No, man. He made "Thriller".
[pause]
Dave Chappelle: Thriller.
Prosecutor: So you'd let your kids sleep with Michael Jackson?
Dave Chappelle: frick NO!