The Mummy (1931) - make up wizard Jack Pierce transforms Boris Karloff into the wrinkle faced Imhotep and into the centuries old Mummy.
King Kong (1933) - they've tried guys in suits and it looks like CGI in Peter Jacksons upcoming Kong but nothing beats the 10 lb. puppet brought to life by Willis O'Brien. Watch as Kong battles: dinosaurs, men and finally WWI era bi-planes to protect Ann Darrow and then cry as Kong plummets to the New York streets.
Mystery of the Wax Museum (1933) - Fay Wray beats on Lionel Atwells face as he carries her to his waxworks. Finally, amazingly, his face cracks and falls off revealing a horribly scarred visage that causes Fay to scream and faint.
The Exorcist - where to start: Reagan's 360 headspin, the pea soup, the "Help Me" that scratches itself on her stomach (from the inside!). I remember when this came out. No one had seen anything like this.
Dawn of the Dead (1977) - from the amazing exploding head 10 minutes in to the various wounds suffered by the zombies and humans a like Tom Savini really earns his money.
The Thing (1982) - this movie got squashed by E.T. at the box office but The Thing features some the most amazing make up effects ever captured on film. From the first transformation in the dog kennel to the jumping blood during the blood test this is Rob Bottin's finest work ever.
Jurassic Park - forgetaboutit! The first time the T. Rex rips through that fence and proceeds to show everybody just who the boss is is a truly awesome movie moment. I still get chills.
Jurassic Park: The Lost World - ok. this movie has two sequences that are awesome: the stegosaurus herd that crosses the stream and the end sequence that features the T. Rex family, a herd of stegosaurs and, finally, a pteranodon that flies at the camera and perches on a tree branch.