Great RPG Blogs:
Roleplaying theory from Ben Robbins — a superb (if infrequently updated) site.
Not a blog per se, but a great resource. Type in a question, get a community of interested roleplayers to answer 🙂
Great Game Mastering advice from an inspirational blog.
Call of Cthulhu Resources:
Arguably the home of Call of Cthulhu online. A wealth of material for Keepers and other aficionados.
Complete collection of Lovecraft’s writings.
Mythos related blog collecting links to useful play aids, props and resources.
Vampire the Requiem Resources:
More editable character sheets than you can poke a stick at.
Other cool stuff:
Home of the indie RPG revolution.
Recommended by a friend, the GMing advice is top notch.