1. Hal 9000. "I can't let you do that Hannibal"
2. Darth Vader. Vader has become an icon for a reason, whereas repetition has diluted Dracula
3. Khan Noonian Singh. KHAAAAAAAAAN!!!!!!
4. Joker. Thoth-Amon has the Conan connection going for him, and is a damn good villain. Joker howver, is something else, he can still scare me with his sheer madness and cruelty.
5. Megatron. I'm a child of the 80s, what more need I say.
6. Napoleon. He's actually out there, being evil, while Sauron does nothing but be some presence.
7. Emperor Palpatine. He took over the freaking galaxy! Burns got shot by a baby. The Emperor wins.
8. Lord Voldemort. The further along the series goes, the better he gets.