The Mayor but I must admit that I clicked Angelus first. The Mayor’s humor and his interaction with Faith push him way over the top though.
Willow and Warren were okay, S6 is my third favorite season.
Adam and The Master were boring. The First was a good concept and I liked the way other characters responded but it was still pretty boring.
Glory annoyed the piss out of me.
I liked the characters and the dialogue, it didn’t really matter to me who they were fighting. That’s why I enjoyed S2 & S3 so much, they really had the whole package for me.
ETA: I’m so glad other people thought Glory was annoying.
Ha My SDMB nick is actually not related to Buffy the Vampire villainess of the same name, but still pretty funny.
Edit - I joined the SDMB in December 2000, Glory’s first ep was Oct 2000. I swear - not related! It’s from something even dorkier than a Buffy episode, if you can believe it.