I don’t really go to many. The long-time RPG forum sites have an unfortunate toxicity which turns me off, and the only blogs that I visit tend to be personal blogs of friends which occasionally feature RPG content. For the sake of this question, though, I’ll count the latter category.
I’ve found that my favorite RPG content on blogs comes from Steve Kenson’s site, which often features wonderful material for super-hero gaming (as you might expect from the designer of Mutants & Masterminds and Icons). His “Re:Animated” series (click the tag on his site), where he examines episodes of superhero animated series with an eye toward what lessons can be learned for superhero gaming, is especially worth digging into.
Here’s Dave Chapman’s video entry for the day: