Dr. Evazan: [explaining] He sez you're a moron.
Luke: Fuck off.
Dr. Evazan: Now lemme tell you something, motherfucka! They tried to put me in the electric chair, but you know why they couldn't? Because I fucked 'em so fucking hard that they...
Luke: Piss off, gay.
Dr. Evazan: Don't make me do ya in, you little fuck!
Obi-Wan: [intervening] Get off his back, you piece of homosexual wank-splat! He's too small for you! Why don't you just go have a pint of piss instead? (he's British after all)
[Dr. Evazan shoves Luke across the room and pulls out a blaster]
Bartender: Hey! What the fuck do ya think you're doing?!
[In a flash, he and his alien companion Ponda Baba are on the floor with a slashed torso and a severed arm respectively]
Luke: Why the fuck did you have to say that? You made the whole thing worse!
Obi-Wan: Scruttocks. Don't fuck with the Jedi Master!
And now for an original one:
Han Solo: Hey, Chewie? Have you got any problems with shit in your fur?
Chewbacca: [growls]
Han Solo: Good enough!
[fart noises]