Wow - 111 comments? I will admit to using Xander fairly often as a bad guy (Hearts Breaking Even) (or a wannabe bad guy, anyway), but I can do that in one fic and turn around in another and make him a good guy (He Aint Heavy, He's My Vampire). Like all the characters from BtVS and AtS he is multi-layered and complex. It's very easy to take his unattractive qualities and emphasize them to make him a major jerk, but it's also possible to look at other traits and emphasize them so that he comes out a nicer guy. If there were a balance sheet of good qualities vs bad ones, chances are it might lean towards bad guy - but I don't think it totally defines him.

I can't imagine hating anyone from the Buffyverse (ok, not too crazy about Warren..). If nothing else, they're all so complex that they give writers tons of room to write them as needed. We should value them for that, if nothing else.