Thirdly, and most favoritely, the iconic wedding scene from The Princess Bride. This might be the second most quoted part of what is, for my money, the most heavily quoted movie of our time. There is something so classically hilarious about an old guy in a funny hat with a speech impediment performing an important act.
You can bet your ass there will be at least two members of the wedding party doing this bit from the rehearsal until the lights go out at the reception.
The best part: The way he says Buttercup something along the lines of "Buttahl-cah-wup"