I love this one from Fried Green Tomatoes:
Sipsey: Oh it don't make no kind of sense. Big ol' ox like Grady won't sit next to a colored child. But he eats eggs- shoot right outta chicken's ***!
And we always use these (obvious ones) from Princess Bride:
Wesley: As you wish. and
Vizzini: INCONCEIVABLE! (with a nod to the follow up line)
Inigo: You keep using that word. I do not think it means what you think it means.
And then often, but for no good reason, one of us will bust out the:
Hello. My name is Inigo Montoya. You killed my father. Prepare to die.
One I love from Hoosiers:
Coach: Strap, God wants you on the floor.
Two awesome "Amen, Sister!" quotes from Bull Durham:
Annie: The world is made for people who aren't cursed with self-awareness. and
Annie: Honey, would you rather I were making love to him using your name, or making love to you using his name?
And, it's new, but few lines have been quoted as much in a concentrated period of time. From Brokeback Mountain:
Jack: I wish I knew how to quit you.
More quotables from Brokeback:
Ennis: There ain't no reins on this one. and
Jack: You know friend, this is a god damn bitch of an unsatisfactory situation.
This is probably a different thread, but I'll toss in WORST MOVIE LINE EVER:
Nobody puts Baby in a corner.