I agree with many films already mentioned (I am a Trekkie addict at 50+ years old) but how could I leave out two films I've seen over a dozen times and still laugh at:
To Catch a Thief (LOVE IT)
Father Goose
Operation Petticoat
Greatest Show on Earth
True Lies (Tom Arnold is such a hoot in this....)
The Birdcage (the remake)
Galaxyquest
Robin Hood (Errol Flynn)
Princess Bride
Dirty Rotten Scoundrels
Ferris Beuler's Day Off
Fried Green Tomatoes (TOWANDA!!!!!)