Monty Python and the Holy Grail. Hands-down one of the most brilliant pieces of comedy ever produced. Surreal, smart, quick-moving, innovative... you name it, they did it right.
Kung Pow: Enter the Fist. C'mon, there was a kung fu fight with a COW! They even used bullet...err, milk-squirt time! But the scene that *really* got me in pain was the intro. The Chosen One, still a baby, is rolling down a rocky hill to escape Master Pain. First of all, he's making vibrating "ah-h-h-h-h-h-h-h-h-h-h-h-h" noises as he bounces along, which is funny enough... but then, he rolls to a stop at the feet of a peasant woman, who picks him up and kisses him, saying, "So cute!". So you think the lady's going to take him home and raise him, as always happens in these movies, right?
Well, no. She turns, and with a perky "bye-bye!" rolls him right on down the hill.
It killed me. Seriously.
Rat Race. Amazing cast, great jokes, even some subtle stuff. Rowan Atkinson *and* John Cleese in the same movie? oh my.
"It's a race! I'm wee-neeng!"
Hot Shots! (and Part Deux) and Scary Movie - I love the parody films where everyone keeps a straight face as everything is just going completely to hell all around them.