There are a few I look at on a regular basis:
Hullabaloo:
http://digbysblog.blogspot.com/
"Digby" always has something interesting and angry to say. He writes what I'm thinking, usually before I've thought it!
Pandagon:
http://www.pandagon.net/
Two writers, Jesse and Amanda. I particularly like Amanda's take on things. She writes a lot about music, too. And I guess because there are two of them, it seems like there's something new on this site every time I open it.
World O' Crap:
http://blogs.salon.com/0002874/
"s.z." is one of the funniest writers on the net. Most of her posts make meciless fun of conservative pundits and bloggers, especially those of the more bargain-basement variety, culminating in her currently ongoing series, "Ultimate Wingnut Challenge."