Hold onto your drawers, and don't piss in 'em! ~ Who else?

EDIT: Forgot a couple of classics -

He's crude, a jerk, he's Rude of the Turks.

Rufus' pocket full at the cafeteria... Rufus' rocket full of materia ~ Both by the joke-teller in Rocket Town, not sure about the last one

And the whole "Who do you like?" conversation between Reno and Rude in Gongaga.