Now, HOW can I pick just one villain?
I like Captain Hook a lot, in all of his incarnations.... Jason Isaacs, Dustin Hoffman, Disney, and the yummy Colin O'Donoghue. Captain Hook is just pain mean. A mean you can sink your teeth into. Metaphorically, of course. Ahem.
Of course, Draco Malfoy. Though, he got less and less villainous as the books progressed, I feel.
Maleficent is kind of a bad ass.
The Wicked Witch of the West, of course. She is Evil. No redeemable characteristics whatsoever.
The Joker. Snidely Whiplash. Lord Voldemort. Darth Vader. Cruella DeVille. The Queen of Hearts. Hannibal Lecter. Scar. Kaa the Snake.
Catwoman. Though she's more of an antihero...
Any of those resonate with any of you?