AllSides, a news aggregator that tries to quantify the bias of publications

AllSides describes how they rate bias - it is supposed to reflect the average judgment of Americans, only reflects the web pages on news (not opinion pieces) and they are continually getting more data and changing. Explanation here http://www.allsides.com/bias/bias-ratings

This has great potential, I'd definitely argue with some of the classifications but giving people on both sides a single site where they can contrast what both sides are saying could begin to heal the country's great divide.

Speaking of bias: the Daily Beast, Politico, and NPR are defined as centrist.