These are my favorite blogs:

A Cardboard Problem
Astros Baseball Cards
Bad Wax
Baseball Cards of the Golden Age
Bdj610′s Topps Baseball Card Blog
Busting Wax
Card Collector Universe Home
Cardaholics Anonymous
Cardboard Gods
Cardboard Junkie
Cardboard Reflux
Cards On Ice your source for hockey card information
Dinged Corners
Lake Effect Baseball Cards
Orioles Card O the Day
Stale Gum
The Angry Sports Card Guy
The Budget Collector
The Easy Life
The Hockey Cards Blog
Topps Traders
Wax Breaker
White Sox Cards