This one's easy. Young Frankenstein. Written by Gene Wilder, directed by Mel Brooks, this film should be used as a textbook example of how to do comedy. If you are unfamiliar with this movie it is a gorgeous parody of the 1950s monster movies, shot in black and white, and starring Gene Wilder, Peter Boyle, Madeline Kahn, Teri Garr, Marty Feldman, and Cloris Leachman. In most of Mel Brooks' movies there are a couple of gags that just don't work, and you overlook them because the rest of the film is so wonderful. There is not a single bad moment in Young Frankenstein. I could go off on a quote fest here, but I'll resist the urge. Suffice to say that this is my all time, hands down, no contest favorite comedy film. Now you take the blonde and I'll take the one in the turban! :-D
Oh, and I almost forgot this brilliant cameo by Gene Hackman.