Not sure why being the most watched means most unbiased. By that token, then ABC News is the most unbiased source since about 5 times as many people watch ABC News every day compared to Fox News. Did you know that? Liberals don't watch evening News as much - they tend to get their info on the internet. Plus the audience is split across many many news sources. But Fox news is still relatively small and niche. Cable News is small and niche. And right-wingers only have fox news. Fox doesn't report news. It doesn't just give facts, it gives commentary. It's more News Commentary and actual information and specifically targets the right wingers. MSNBC targets the left, the other news sources go for broad audiences built around the center. So yes, MSNBC & FOX are the most biased by far.
When they announced the Sandusky verdict I turned on the TV and my choices were shepard smith, chris matthews, lou dobbs, nancy grace, anderson cooper, and I think maddow. I gave all except nancy grace about 10 seconds and was forced to watch cooper on cnn as least offensive.