Rutger Hauer as Jon Ryder in The Hitcher. And an honorable mention to the only role he ever played as a bad guy, Henry Fonda as Frank in Once Upon a Time in the West.
Marlon Brando as Colonel Walter E. Kurtz in Apocalypse Now. Any man that has a hanging corpse for a flag at his boat dock and human heads decorating his front lawn and the steps leading up to his house is one bad mofo. Kevin Spacy as John Doe in Se7en. Once again. Any man that would express mail your pregnant wifes head to you when your located in the middle of nowhere is one bad mofo!
While I don’t ordinarily contribute to necroposting (this thread was originally created back in 2005) my favorite villain is Pinhead from the Hellraiser series Hotwater
Vincent Price's character in The House on Haunted Hill ('59) Alex de Large in A Clockwork Orange Top Dollar in The Crow The Goblin King (David Bowie <3 ) in the Labyrinth
Christian Bale as Patrick Bateman in American Psycho, Vinnie Jones as Bullet tooth Tony, Tobin Bell as Jigsaw.