Politics1.com
massive aggregation of political data including thorough third party coverage.  I mean, where else have you ever heard of the Christian Falangist Party of America?

The Next Right  http://thenextright.com
http://thenextright.com/patrick-ruffini/obama-had-13-million-e-mail-addresses-and-raised-half-a-bill ion-dollars-online

The next right is a conservative political strategy blog run by sane people, not to be confused with some of the more rabid commentary blogs.

Daily Kos
http://dailykos.com/
MyDD (Direct Democracy)
http://www.mydd.com/

Progressive Liberal blogs.  A considerably larger readership leads to more chaff among the wheat grains.  However, the blog that substantially installed Governor Dean as DNC chair and launched the 435 District strategy (50 states was Dean's idea) continues to produce some political discussion.

FiveThirtyEight.Com      Pollster.Com
Polling aggregation sites.  Nate Silver, who runs FiveThirtyEight.Com appears to have done the best job of estimating where the aggregated polls are.