Excluding the S8 comics as I have yet to read them, and I'm not good at fleshing out posts like this.
Someone voted Adam? For serious? God damn. Anyway, the Mayor or Glory all the way. Caleb would have been up there as Nathan Fillion = boners.
If you havn't read them yet, don't bother, the Twilight reveal was awful. The poll is still good, suppose Willow shouldn't count as she was only 'dark' for 3 episodes.
Angelous, not because he´s strong or powerfull, but because he´s a master on psycological warfare and terror. I´m surprised Smurffete is not there, but then again Illyria was a villain for a short time, if anything she´s currently an anti-hero.
I'd have to say it's pretty close between the Mayor and Glory. I mean, my penis tells me Glory, but my head tells me the Mayor. I'm so conflicted. Edit: Bah! I really gotta start paying attention to what I'm typing. My apologies for the typos.
First off, can I just say it warms my heart that there are other Buffyverse fans on this board...... ahhhh..... Anyhow, it's a tough call between the Mayor and Angelus; I'm gonna have to go Angelus, though, just because of the emotional arc that the second season took. Least favorite is the First. Just didn't really get the development it needed as a villain. Good thing the final season had Caleb to round out the villain roster. Also not a big fan of Glory, but that's really only because of the uneven acting by the actress who played her. With a better performance I likely would have enjoyed her more.
Glory. She was just so much fun, being all crazy and hot and crazy. Plus, Season 5 is probably just my favorite over-all.
Angelus - the best villains are the ones the heroes have emotional ties to. Add in Spike and Drusilla, and you had a perfect season of the show. Buffy reached it's peak with episodes like "Passion" and "Becoming", not only because they were superbly written, but also because it hit you on the emotional level. Angelus' opening and closing monologues in "Passion" still gives me chills.
Angelus all the way! Best villain ever, he's just so sick... ^^Yup, Passion was epic and chill-giving. My favorite episode. Because of Angelus' evil twistedness and Giles' awesome torch-weildingness and then that bit at the end with him and Buffy that makes me cry... I haven't seen all of Buffy yet, though, I just got into it this summer. lol I'm obsessed now, in early season 6... I gotta say, I'm loving the trio, too. Nerdiness amuses me. Just because they're so pathetic. And they're frighteningly reminiscent of me... Minus the pervertedness, but other than that... yeah. xD
Definitely the Mayor, followed by Angelus. Season Three has always been my favorite, followed closely by Two. I'm sure part of that has to do with Faith, who is way hotter than Glory.