Here's a couple I read on a regular or semi-regular basis:
analog_industries | analogindustries.com - Chris Randall's blog. Hilarious, well-written, biting, everything a good blog should be. The guy makes good plug-ins as well, although I'm not as big a fan of his music as others.
ProToolerBlog - pretty Pro Tools centric (who'dathought?) - but a useful resource nonetheless. Occasionally errs on the side of too many outright press releases, not enough commentary, but it keeps me up to date with what's new in RTAS land.
Create Digital Music - I used to like this one more, it's pretty much found its' niche in electronic music now which isn't my thing but still has the odd good post about something more general.
Music Thing - Music Thing - been around for a while, arguably not updated enough, because what is posted there tends to be very good. Covers a lot of ground!