Online Community for Artists

In Minnesota we have MNArtists.org and it is great but I find that the online discussions aren’t as rich as they could be.

Please comment on your favorite online community for artists. Where do you go to post questions about techniques, about the art market, about art history, or to tell stories about yourself and your work. Have you visited other such sites? What makes one stand out?

I would like to have an active, open, and safe dialog about art making. I look forward to any suggestions and will post more about those I have tried.