Sorry to resurrect this dieing thread, but with the completion of Super Paper Mario, I've got a new one for the books:
"To feel sadness is to be alive, but as long as you're alive, the future is a blank slate..."
"...and with that, I am hungry"
Any lines from the Mario RPG series is good. I'm especially fond of Super Mario Superstar Saga's villian, Fawful. and the fact everything he says is gold. "Fink-Rat, have you readiness for this?", "I HAVE FURY!", and my personal favorite, "Your lives that I spit on are now but a caricature of a cartoon drawn by a kid who is stupid!"