The following are blogs that I find interesting and useful. I do not necessarily endorse all they say, but they are written by intelligent and thoughtful people. They are in no particular order.
Black, White, and Gray: Christianity and sociology
Her.meneutics: For Christian women, but interesting for the other half
Mark Shea: A variety of things Catholic
Bad Catholic: Longer posts with intelligence and wit.
Happy Catholic Bookshelf: More or less exactly what it says on the tin
The Personalism Project: A site dedicate to the philosophical idea of personalism.
Project Unbreakable: A powerful response to rape and abuse.