The single most memorable quote for me is:
"I'm going to make him an offer he can't refuse"
My personal favorite though, is much harder to pin down - changes frequently
This one still cracks me up from Armageddon "He's got space-dementia!"
Also: "I've had it with these motherf*****g snakes on this motherf*****g plane!"
BTW, YOU SACK OF WINE!