There's a good one where they show two of the characters sitting down holding one-another, and it's obviously a very emotional moment, and one of them sneezes!
okay, so you had to have been there. I thought it was damn funny.
Of course, not as funny as the outtake where one of the characters accidentally shoots the main character, slowly walks over to her, nudges her with his foot, then puts down the gun and tries to walk off as though it wasn't him. That's probably the best one.