Top 15 economics blogs (i.e., competitors).
1. http://krugman.blogs.nytimes.com/ (Paul Krugman, Nobel Prize 2008, Princeton U.; one of Time magazine's top 25 blogs, together with Freakonomics)
2. http://opinionator.blogs.nytimes.com/author/joseph-e-stiglitz/ (Joseph E. Stiglitz, Nobel Prize 2001).
3. http://delong.typepad.com/sdj/ Brad DeLong (UC-Berkeley)
4. http://economistsview.typepad.com/ Mark Thoma (U. of Oregon) (which also includes a very comprehensive list of economists blogs on the right side column; he was my Professor at UofO).
5. http://rodrik.typepad.com/ Dani Rodrik, Harvard U. (on development economics)
6. http://freakonomics.com/blog/ run by Steven Levitt (U. of Chicago) and Stephen Dubner (journalist), co-authors of the book.
7. http://www.econbrowser.com/ James Hamilton, UCSD; and Menzie Chinn, U. of Wisconsin (also an extensive list of blogs on the right hand column).
8. http://blogs.reuters.com/felix-salmon/ (Felix Salmon, on Finance and Economics)
9. http://angrybearblog.com/ (“Slightly left of center economic commentary on news, politics, and the economy.”, run by a group of economists and finance Ph.D.s)
10. http://www.economonitor.com/analysts/ (RGE Analysts, Chairman Nouriel Roubini, NYU).
11. http://www.ft.com/intl/comment/blogs (Financial Times blogs. They are all great. Especially Buiter, Crook, Wolf, and Alphaville)
See, in particular, the Economic Forum: http://blogs.ft.com/economistsforum/
12. http://www.economist.com/blogs/freeexchange/ (Economics blog on The Economist)
13. http://www.businessweek.com/blogs/econochat EconoChat captures Tom Keene's thoughts on economics, finance and investment
14. http://seekingalpha.com/ (More financial than economics)
15. http://business.time.com/category/curious-capitalist/ Rana Foroohar is TIME's assistant managing editor in charge of economics and business.
Honorable mention. http://www.progressive-economics.ca/ Progressive Economics Forum.
I would have added Brad Setser (http://blogs.cfr.org/setser/), but he has joined the Obama administration.
Here are competing lists:
http://online.wsj.com/article/SB124769381962047691.html (Wall Street Journal)
Whose economics blog is: http://blogs.wsj.com/economics
http://content.time.com/time/business/article/0,8599,1873144-3,00.html (Time CNN)
http://business.timesonline.co.uk/tol/business/industry_sectors/media/article1923706.ece (The Times, UK).
http://www.intute.ac.uk/blog/2008/03/12/favourite-blogs-economics/ (Intute, UK).
UPDATE: Links have been updated as of December 2013.