I gotta go with a tie, Animal House and Holy Grail...

"Seven years of college down the drain"

"What? Over? Did you say over? Nothing is over until WE decide it is! Was it over when the Germans bombed Pearl Harbor?"... " Germans?" " Forget it, he's rolling"

" May I have ten thousand marbles please?"

and the funniest lines of all time " Are you suggesting coconuts migrate?" and "Strange women, lying in ponds, distributing swords is no basis for a system of government"