Some of the blogs from my RSS feed, mainly but not exclusively .NET:

Scott Hanselman

Martin Fowler

Coding horror

Fabulous adventures in coding (Eric Lippert)

Zed Shaw (still on my list even though he seems to have largely abandoned tech)

Ayende Rahien

Steve Yegge

Schneier on security

The Light Cone (Brian Beckman)

The Shade Tree developer (Jeremy Miller)