Every morning at work I start my day off by checking programming.reddit.com and reading three programming blogs:
Coding Horror, Joel On Software, and The Old New Thing.
I find these particularly insightful on a variety of subjects, ranging from good UI design to the oddities of the Win32 API and reasons why they exist. Highly recommended reading for everyone out there.
To close with a question, what other programming blogs do you read on a regular basis?