No matter how you dice it, watching actors screw up and laugh uncontrollably is extremely funny. In some instances the movie outtakes or "gag reel" (that's what she said) are actually funnier than the movie itself. This is why I think it's time for a Hollywood studio to grow a pair and release a movie that's only outtakes because I bet they'd be pleasantly surprised with the box-office results. This concept also applies to the people that make the movies where the people don't wear any clothing.
#10 Superbad - And to think we're only about ten years away from watching the tragic McLovin: E! True Hollywood Story that talks about his short-lived marriage with Courtney Love and severe addiction to McDonald's.
#9 Cannonball Run - The greatest in a long line of Dom Deluise's famous uncontrollable outtake laughter attacks.
#8 Knocked Up - I'd be lying if I said I hadn't watched this movie at least 30 times on HBO over the last year.
#7 Toy Story & Toy Story 2 - It's doesn't get much better than Prospector "Stinky" Pete giving himself the packaging box dutch oven treatment.
#6 The 40-Year Old Virgin - You know how I know you're gay? If you don't think these outtakes are funny.
#5 Talladega Nights: The Ballad Of Ricky Bobby - Will Ferrell and John C. Reilly should do a movie together every year for the rest of their lives
#4 Rush Hour - Jackie Chan has always been the master of outtakes including the Armour of God where he supposedly cracked his head open.
#3 Liar Liar - And to think that Jim Carrey got to spend an entire day in an elevator with Krista Allen and her epic chest muffins.
#2 The Nutty Professor - One day there will be a movie dedicated to fat people farting and what a great day that will be.
#1 Grumpy Old Men - I don't know about you, but I could listen to Burgess Meredith say dirty euphemisms for sex for at least two hours.