Justin Alexander runs The Alexandrian, a blog that I've read and followed for some time now. He and I do not agree on a lot of things, but I am wholly in accord with--and supportive of--his efforts to bring back old forms of running tabletop RPG campaigns back to a wider audience, and in doing so explain how and why things work as they do (or did). In particular, I am a big fan of his Open Table posts and Megadungeon posts. The rest depends on if you're into what he talks about, but that? Golden.