All About Microsoft by Mary Jo Foley
Keeping an analytical eye on Microsoft, Mary Jo Foley talks about both their present and future (both projected and from leaks).
Coding Horror by Jeff Atwood
A programmer posting interesting thoughts about programming.
Daring Fireball by John Gruber
An Apple blogger who posts interesting links and fascinating analysis about the major players in the computing industry.
The Ed Bott Report by Ed Bott
While writing primarily about Microsoft and its competitors, Ed Bott tends to straddle both sides of the line, and isn't afraid to speak negatively about either.
I Started Something by Long Zheng
Long Zheng writes about the small, but important, things in Microsoft and Windows.
The Old New Thing by Raymond Chen
Raymond Chen presents the history behind decisions, features and APIs in Windows.
Real Dan Lyons by Dan Lyons
An Android and Apple fan with some certainly interesting opinions about various things.
Supersite for Windows by Paul Thurrott
It's there in the name. Paul Thurrott focuses on news, screenshots and, sometimes, reviews of the software and hardware from Microsoft and their competitors.
Within Windows by Rafael Rivera
Rafeal Rivera deals with some of the more technical aspects of Windows, Windows Phone, and their apps.