'Are we a teapot?'
 from the guy on the 'How to be a Man' tape
 Kevin Kline's character in In and Out

'Great, I kidnapped by fucking parents.'
 Denis Leary in the Ref

'If shit was worth something, poor people would be born without assholes."
 Eddie Murphy in Another 48 Hrs.

IMHO Best cuss artists:
 Samuel L. Jackson - when he starts to swear, look out, someone's going to get it.
 Denis Leary - can do some unbelievable rants.

Feel free to add to the list.

AK-47 - When You Absolutely, Positively Got To Kill Every Motherfucker In The Room. Accept No Substitutions

"Yes...they deserved to die and I hope they burn in hell!""

"If you don't give Big Ed some air, he's going to piss all over your side of my body" - Steve Martin, All Of Me

Val Kilmer and Some Hot Chick in Real Genius:

Kilmer - "So you'll let me know if there's anything I can do for you - or, more to the point - to you?"
Hot Chick - "Can you pound a six inch spike through a board with your penis?"
Kilmer - "Ahhh... not yet"
Hot Chick, sadly - "Well, a girl has to have standards."

and last but not least -

"I haven't been fucked that good since the sixth grade" - Helen Bonham Carter, Fight Club

From "Smokey and the Bandit".  
Ark. sheriff, " You say you are a sheriff?".
Sheriff Justice, Jackie Gleason, "I'm in high speed pursuit, don't you hear good?"
Ark sheriff, "I hear pefictly. The fact you are a sheriff is not germain to the situation."
Sheriff Justice, "The god damn Germans got nuthin to do with it."

From"The Adventures of Robin Hood"
Sheriff of Nottingham,"So, you're over taxed."
Robin Hiid, Erroll Flynn, "Over taxed, over worked. Payed off with a kniff, a club or a rope."
Lady Marion, Olivia de Havillond, "Why, you speak treason."
Robin, "Fluently."

From "The Professionals"
Mr. Grant, "You bastard!"
Lee Marvin's charecter, "Yes, sir.  In my case, an accident of birth. You, you're a self made man."

From "Diamonds Are Forever"
Tiffany, Jill St.John, "Which do you prefer, blondes or brunettes?"
Bond, Sean Connery, "Well, providing the collars and cuffs match."

Urban Cowboy
"Cissy, I apologize clear back to the first time I hit you"

"Get off the babysitter, Joel."  Risky Business.

This might not be a direct quote, but a great scene in a great movie....Humphrey Bogart to Lauren Bacall (she was such a hottie!): "If you need me just whistle.  You know how to whistle don'tcha: you just put your lips together and blow."  (Was that from "To Have And Have Not"?)

But, it was Bacall that geve the line.

Michael Caine in the Italian Job

"You're only supposed to blow the bloody doors off"