Oy that's a lot... EDIT: And I should have read the first post that I only had to care about the first 5.
17./18. Viper Daimao/Santa Claus: No.
14./15./16. Grimlock/Richard Rhal/CyberSix: Never heard of them!
12./13. Red Mage/Sarda: Static, they are only amusing as part of the ensemble (my name is mostly based around the attitude behind the title, not the character).
11. Cuthulu (spelling?): Never read the books, but I can get behind the concept a little.
10. Merlin: I know there's some awesome book with him in it, but the only reference I have for him is the Disney Movie and some memories of the legend. He gets placed here only because I loved that movie as a kid!
9. Severus Snape: If he was in better books (or the hands of a better writer) I might care more. As is, he's okay!
8. Vivi: He's adorable, powerful, and has interesting struggles, but he never attached to me as much as others.
7. Spiderman: He has interesting and has funny quips, but I feel stronger for other characters on this list.
6. Batman: No, I'm not a great Batman fan. He's awesome and a genius, but eh.
5. Sokka: Badass Normal (without being ridiculously overboard) and funny.
4. Dr. Manhattan: Good guess, but I just like the quote! He's a powerful character that's chained by fate, but it's a dick to relate to him.
3. Kamina: The epitome of a determinator and a complete and utter badass, but there's stronger candidates.
2. V: Perfect candidate for the merits and failings of the ego.
1. Joker: Ah sociopaths. By their very existence they call into question society's ethical presumptions. The mania, humanity, and tragedy encapsulated by the Joker resonates strongly, to the extent that he essentially pulled the entire movie. You think it's hard to feel for a mass murderer with no morals until you come across a well-written one!
Just as a note, Ender would have been an instant win.
Take it away Garud!