If you're talking about the giant snappin' worms...
.. a good friend of mine helped work the armature & pneumatics on the worms. He said they had a real blast screwin' around with 'em. I only saw the first one, but it was a fun movie!
also..
I just wanted to add Barton Fink to the list, my favorite movie probably.
and, even if they were previously mentioned:
Illusionist, Paul Giamatti was brilliant!
Old Boy
Audition
Dark City
Jay & Silent Bob Strike Back
Starship Troopers, never tire of it.
Nosferatu, the first one.
Art School Confidential
After Hours
The Aristocrats
Carnival of Souls
Donnie Darko
The Iron Giant
Picnic at Hanging Rock
The Last Wave
Sin City
Spirited Away
12 Monkeys
American History X
Amadeus
Chinese Ghost Story
Iron Monkey
Clue
ok I'll stop now, I could go on and on...