Not really a single quote, but an exchange between four characters in Butch Cassidy and the Sundance Kid (one of my favorite movies):
Harvey Logan: Guns or knives?
Butch Cassidy: Neither?
Harvey Logan: Pick.
Butch Cassidy: I don't want to shoot with you Harvey.
Harvey Logan: [draws a big knife] Anything you say, Butch.
[Butch walks over to Sundance]
Butch Cassidy: [in a low voice] Maybe there's a way to make a profit in this. Bet on Logan.
Sundance Kid: I would, but who'd bet on you?
Harvey Logan: Sundance, when we're done, and he's dead, you're welcome to stay.
Butch Cassidy: [low voice, to Sundance] Listen, I don't mean to be a sore loser, but when it's done, if I'm dead, kill him.
Sundance Kid: [low voice to Butch] Love to.
[waves to Harvey and smiles]
Butch Cassidy: No, no, not yet. Not until me and Harvey get the rules straightened out.
Harvey Logan: Rules? In a knife fight? No rules.
[Butch immediately kicks Harvey in the groin]
Butch Cassidy: Well, if there aint' going to be any rules, let's get the fight started. Someone count. 1,2,3 go.
Sundance Kid: [quickly] 1,2,3, go.
[Butch knocks Harvey out]
Flat Nose Curry: I was really rooting for you, Butch.
Butch Cassidy: Well, thank you, Flatnose. That's what sustained me in my time of trouble.