After much research, study, and speculation, I have narrowed it down to 11 Disney villains who are ultimately superior and awesome, based on voice, looks, powers, and/or theme song (if they have one).
I haven't gotten a particular order for them in coolness, but I do know they are:
1. Ursula, from The Little Mermaid. Evil, white-haired, sarcastic tentacled-woman. What's not to like?
2. Medusa, of The Rescuers. Greedy, sadistic, red-haired woman. There's a pattern here.
3. Jafar, the main bad dude in Aladdin. Doesn't have a theme song in the first movie, and the second is rather mediocre in my book. But his powers are uber-AWESOME.
4. Cruella de Vil, from 101 Dalmatians. Fur-wearing, slightly crazy dog-killer, known as the devil woman. Great theme song.
5. Maleficent, the bad fairy or whatever in Sleeping Beauty. Her song, if you can call it that, doesn't really have any words, just a creepy, bone-chilling clarinet solo. Plus, she has one of the best lines, describing her minions: "They're all hopeless. A DISGRACE to the forces of evil."
6. Frollo, ala The Hunchback of Notre Dame. Sings one of the best songs in Disney history, and his religious hypocrisy is a refreshing relief from the usual cheesy nauseous villains they think up. Even if he does wear a dorky-looking hat.
7. Captain Hook, from Peter Pan. He's hilarious, temperamental but cowardly, and always looking for loopholes in his promises. He can't hold a candle to Dustin Hoffman, but he's the next best thing.
8. Shere Khan, out of The Jungle Book. One of the BEST voices ever! And the way he is politely threatening causes chills every time!
9. Doctor Facilier, from the latest The Princess and the Frog. He has the best song in the movie, and is sort of a cross between Hook and Cruella de Vil. This makes him automatically awesome.
10. Scar, the deprived, vengeful brother from The Lion King. Kind of a stereotypical theme, but then again, most of these are. And there is probably no one with half a brain who would deny that his song is magnificent, and great, and any other positive adjectives possible.
11. Hades, Lord of the Dead, a la Hercules. He talks, looks, and acts great. And the flaming blue hair only adds to his image.
If anyone has any other suggestions for the list, please let me know.