The Guardian just produced a list of 50 most influential blogs. I don't necessarily think this list is correct, but of the top ten five are in my bookmarks. As those who comment often say, Your Mileage May Vary (YMMV).
1. The Huffington Post (huffingtonpost.com): high-minded, mostly boring left wing commentary.
2. Boing Boing (boingboing.net): all things cool, open source, and DIY.
3. Techcrunch (techcrunch.com): too businessy and silicon valley for me.
4. Kottke (kottke.org): haven't checked this one, but often see references to it.
5. Dooce (dooce.com): a sort of crazy mom, calls a shit a shit.
6. Perezhilton (perezhilton.com): whatever.
7. Talking Points Memo (talkingpointsmemo.com): lefty journalism, with a recent obvious injection of cash.
8. Icanhascheezburger (icanhascheezburger.com): I have no idea.
9. Beppe Grillo (beppegrillo.it): comedy?
10. Gawker (gawker.com): I like Wonkette better; why should I care about J Lo's ass?