There's one in Good Morning Vietnam - don't know if I should post the actual line or not, might get me in trouble - right after Robin Williams has been notified of his discharge and a flight home the next day...If youv'e seen the movie you should know what I'm talking about. And then Commanding Officer for the entire station a)sends Williams' CO to Guam, and b) actually agrees with the line I was talking about.
In Signs: Mel Gibson asks the other guy (can't remember his name, but not one of the kids - it's the guy that lived in the house with them) if he believes in miracles. His response is just hilarious. I would try to post this one, but I can't remember it word for word; I'd probably butcher it. Besides, The whole atmosphere of the movie just adds to the line, it's one of those "you had to be there" things.
Nate