Mines Fanfiction.net or Livejournal for Fanfics. But if I'm making Icons/Wallpapers it's DeviantArt.
FF.net! ^_^
MySpace has got a great Emily Procter site, next to that one, it's Livejournal, FanFiction.net or this one. :)
ff.net of course
I like posting on my Livejournal because I can put the graphic arts and the fics together. I use a program called semagic and it's very easy to post to my own journal and then post a link on my favorite LJ communities for the fandom the art/fic is for, to my own post.
My favorite place to post Spike/Buffy fiction is Elysian Fields.
I get more reviews on my LJ and Elysian Fields than other places. It's a vain reason for them to be my favorites, but there you have it. :)
ff.net for fanfic and deviant art for fan-art.