I think CNN, Fox News and MSNBC are all biased to some extent. Personally I tend to watch Fox News more but I do watch CNN. I usually watch Anderson Cooper 360, Lou Dobbs Tonight or Wolf Blitzer on CNN, while on Fox I tend to watch Hannity & Colmes, Special Report with Brit Hume or The O'Reilly Factor (I know a lot of people here probably don't like him....) I think MSNBC is probably the most left-leaning of the networks. I've watched them from time to time and they seem to really lean to the left. In all honesty, I can see why MSNBC has such low ratings. CNN leans to the left at times, but has leaned right at times too. They just seem to lean more left than right. Then there's Fox News, which does tend to lean more towards the right, but it has leaned left at times too. I look at Fox as the opposite as CNN seeing as it leans more right than left while CNN leans more left than right.
I think the networks should refrain from attacking each other and stick to their own operations. In my opinion, the attacks on other networks makes them look trashy.