http://www.blogcatalog.com/

http://www.bloghub.com

http://www.bloghints.com/

http://www.blogdirectory.net/

http://technorati.com/blogs/directory/

http://www.wilsdomain.com/

http://blogville.us/

http://www.blog-directory.org/

http://dir.blogflux.com/

http://www.bestblogs.org/

http://alltop.com/

http://www.blogarama.com/

http://portal.eatonweb.com/

http://blogs.botw.org/

http://www.bloggapedia.com/

http://www.totalblogdirectory.com/

http://www.spillbean.com/

http://www.blogtoplist.com/

http://www.toprankblog.com/rss-blog-directories/

Great list of bloggers to follow on the GrowMap blog at:
http://www.growmap.com/intelligent-bloggers/

Here's the post:

Intelligent Bloggers to Consider Reading
May 13, 2009

Looking at analytics today we noticed that those who visit from the blogs of other friendly, intelligent bloggers are reading many more posts when they visit than those arriving from other sources. We thought our readers would appreciate knowing specifically where these other friendly blogs full of quality information can be found.

There are some very helpful Lists at Crenk.com (http://crenk.com/)

Great list of the best Social Media news sites for various markets at http://crenk.com/the-best-social-media-news-sites-for-various-markets/

Digital Music Blogs to read every day at http://crenk.com/top-5-digital-music-blogs-that-you-should-ready-on-a-da...

20 Twitter Applications Everyone Should Be Using at http://crenk.com/20-twitter-applications-everyone-should-be-using/