Voted for Angelus. I just for the first time watched the entire run of BUFFY and ANGEL last year. I have been a Whedon fan since FIREFLY but never got around to checking out BUFFY until the one-two punch of CABIN IN THE WOODS and AVENGERS last year finally got me motivated. When watching season two and seeing the episodes when Angelus first appears and does the things he does (especially that ONE thing he does, which I won't spoil for anyone who hasn't seen but it involves someone who was involved with my avatar) I really couldn't see how they were going to do an entire show with this son-of-a-bitch as a hero. How could he redeem himself after that? (Of course during BUFFY's second season no one had thought of a spin-off yet)
I thought Angelus was a little neutered when he came back on ANGEL. He didn't seem nearly as evil.