I'll also copy-and-paste myself in with some minor editing.
It sounds like a downer, and I guess it's not quite a blog, but I've been a fan of Stupid Comics for a long while:
http://www.misterkitty.org/extras/stupidcovers/"What's this? A paunchy hand points a tiny pistol at easy-to-draw silhouettes of a man, some planes, and giant penises? Luckily a small boy hugs Fidel Castro..." You'll have to find and read the rest of the article for yourself (OK, it's the Dell Werewolf story).
I'm also down with the already mentioned Flashback Universe (and Jim Shelley sometimes wanders by picking up comics to offer), though I've been...somewhat less impressed with the writers other than Jim.
The Absorbascon is now dormant, but is still frequently entertaining and insightful:
http://absorbascon.blogspot.com/Siskoid also has his moments, though he's a little too methodical for me to be a constant reader--for example, capsule-reviewing everything ever Star Trek:
http://siskoid.blogspot.com/And there's also some great material at Dial B:
http://www.dialbforblog.com/There's some mediocre stuff where he just posts images with little to no commentary (presumably because "Robby" is a graphic designer), but there's also neat stuff on Batman's origins and (the last articles listed) probably the best letterer in the business. Yes, I said letterer. And no, I don't mean the Charlton cereal box printer, though that would be a great article to read.