My favorites are the general discussion, author inquisition, and fic talk. I like the fanfic-related stuff because that's what makes this board different from other forums. It's nice to talk to other authors who write in the same fandom as you. I love writing tips, all of those surveys, and other things designed to hone writing skills (except the actual "write a short story" challenges - I don't really get into those LOL; that's just me).
I think a character development board would be really cool. I've got some character surveys I've seen places that I could contribute.
The Confessional thing on my board came as a suggestion from one of my posters, and I think it's a nice idea. People could also put that stuff in the Chatterbox though, so it doesn't matter either way.