E.C. Henry at 2010-01-02 13:32:39:

You got a lot of good ones on that list, Scott. All deserving. Here's a couple more of my all-time favorite villians I think SHOULD be on that list:

Det. Jimmy Shaker (Gary Sinese in "Ransom" 1996)
Col. William Tavington (Jason Isaacs in "The Patriot" 2000)
Stansfield (Gary Oldman in "The Professional" 1994)
Carter Burke (Paul Riser in "Aliens" 1986)

- E.C. Henry from Bonney Lake, WA

Just_Hiltz at 2010-01-02 19:51:20:

Very interesting question. I'm going to go back in film history to my earliest and perhaps the best "villains" and also this is to re-enforce the fact that the better the villain the better the hero...
Basil Rathbone in "the Adventures of Robin Hood" and "The Mark of Zorro".
Eduardo Cianelli-"Gunga Din"
Cedric Hardwick " The Hunchback of Notre Dame"
Frank Thring as Aella in "The Vikings"
Frank Allenby as Ulrich the Hawk in" The Flame and the Arrow"
Walter Matthau as Bodine in " The Kentuckian"

Stephen Boyd as Massala in "Ben-Hur"
Richard Boone as Cicero Grimes in "Hombre"

Fredrick Forrest as Blue Duck in "Lonesome Dove".
Tie between Karl Maden and Martin Landau as Tom Fitch and Jesse Coe in "Nevada Smith".
Sir Lawrence Olivier as Crassus in "Spartacus"
Lee Marvin as Liberty Valance in " The Man Who Shot Liberty Valance"
I could go on and on but...
The intensity of the villain defines the magnitude of the protag's task!!
You get the point right?

Patrick at 2010-01-02 23:08:19:

All great, especially happy to see Gary Oldman from True Romance up there. Here are some others you can't forget:

Longshanks, King Edward I (Patrick McGoohan "Braveheart" 1995)

The Humungus (Kjell Nilsson "The Road Warrior" 1981)

Terminator (Arnold Schwarzenegger "The Terminator" 1984)

Agent Smith (Hugo Weaving "The Matrix" 1999)

Brick Top (Alan Ford "Snatch" 2000)

Noah Cross (John Huston "Chinatown" 1974

Captain (Strother Martin "Cool Hand Luke" 1967)

JD Walters at 2010-01-03 02:27:52:

From that list my personal favorites are Heath Ledger's Joker, Hannibal Lecter and Anton Chigurh. What do they all have in common? They are all inscrutable. As Alfred said in "The Dark Knight", some men aren't looking for anything logical. They can't be bought, bullied, reasoned or negotiated with. Some men just want to watch the world burn.

I find that the most terrifying villains are the ones who don't act out of identifiable motives. We can wrap our minds around the racially motivated 'nativist' (Bill the Butcher), the ultra-patriotic military officer in the grip of nationalistic (read demonic) ideology (Captain Vidal), even the extreme adrenaline junkie (Stuntman Mike)! But when a villain seems to lack any of this all-too-human motivation, but instead strikes and wreaks havoc and chaos for no apparent reason, whose morality seems to be on a transcendent plane, we don't know what to do with them. They almost seem to be creatures from another world. We can't wrap our minds around them. That's what makes them great villains.