Charlie's Diary, the blog of science fiction writer Charles Stross. Usually brilliantly insightful.
Boing Boing, because I think they probably don't get enough hits.
Whatever, John Scalzi's blog. I don't actually even read his books (though I imagine I'll get around to it at some point) I just really like his blog.
Indistinguishable From Magic, a blog by Aaron Diaz, the writer and artist of Dresden Codak, which is one of the best comics.