Here are some of my favorite websites for election commentary:
The Caucus: New York Times Political Blog
Although the caucus used to be less active than other political blogs, coverage has been picking up as of late. Caucus writers, especially Matt Bai, deliver insightful, uncluttered, and interesting analysis. This is the first site that I consult.
The Fix: Chris Cilizza's Politics Blog from the Washington Post
One of the best on the web, Cilizza's blog delivers great commentary.
The Stump: The New Republic's Blog
The New Republic offers some of the best analysis on both parties.
Marc Ambinder's Blog on The Atlantic
A fair and incisive blogger, Ambinder is another must read.
If you Have Time
The Trail: A Daily Diary of Campaign 2008
Has more information but less insight than the above.
More cluttered than the rest, although I enjoy Democratic and Republican Blogs of Smith and Martin
Real Clear Politics
Gathers numerous articles and summerizes polling data
A Few Others
The Nation's Blog
Trailhead: From Slate.com
Slate usually has an interesting article or two on the election