There have been a lot of studies on media bias, one of the most detailed came from George Mason University which measured the time spent on each side of an issue as well as the number of guests representing each side. That study showed that, in balance with the country, all the media is leftward slanting, even Fox, although Fox and Drudge where closest to the middle, being the most balanced.
Here is the detailed study.
mason.gmu.edu/~atabarro/MediaBias.doc
Thank you for posting something that someone might actually learn something from.