Blogosphere

http://implementingscrum.com by Mike Vizdos

Agile & Business by Joe Little

http://www.notesfromatooluser.com/ by Mark Levison

http://silkandspinach.net/ by Kevin Rutherford

http://www.agileadvice.com/ by Mishkin Berteig and many Guest Authors

http://www.trailridgeconsulting.com/ by Pete Behrens

http://undefined.com/ia/ by John Brothers

http://on-agile.blogspot.com by Ryan Cooper

http://chrissterling.gettingagile.com/ by Chris Sterling

http://blog.gdinwiddie.com/ by George Dinwiddie

http://www.estherderby.com by Esther Derby

http://xndev.blogspot.com/ by Matt Heusser

http://www.jamesshore.com/Blog/ by James Shore

http://lauploix.blogspot.com/ by Laurent Ploix

http://www.futureworksconsulting.com/blog/ by Diana Larsen

http://xprogramming.com/xpmag/index.htm by Ron Jeffries (not quite sure if it qualifies as a blog; on the bubble for that...but very useful in any case)

http://blog.lundak.org by Jiri Lundak

Succeeding With Agile by Mike Cohn

http://blog.crisp.se/henrikkniberg/ by Henrik Kniberg

all about agile | by kelly.waters

Net Objectives Thoughts Blogs and Podcasts on Lean-Agile by Net Objectives

http://ericlefevre.net/ by Eric Lefevre

Adventures in Agile Software Development and Scrum by Kane Mar

3Back Thoughts - The 3Back Team

Scrum Breakfast -  Discussions around Scrum, by Peter Stevens

The Agile News - Community filtered agile news.

The Atlantic Dominion Solutions blog - by Robert Dempsey

Agile Voices is an aggregator of agile related blogs

http://agileworld.blogspot.com  by Venkatesh Krishnamurthy

www.agilebob.com by Bob Hartman (Agile Bob)

http://agilefun.com by Jürgen De Smet

http://danielbrolund.wordpress.com by Daniel Brolund

http://agileanarchy.wordpress.com/ by Tobias Mayer