Fox's straight news is the most balanced of any of them.
Their opinion shows make no bones about their bias. I greatly prefer that to those who try to pretend to be unbiased while using the editorial process to tilt the news- that would be CNN, ABC, NBC, and CBS. What they're doing amounts to nothing less than propagandizing.
While I disagree with the opinions on MSNBC for the most part, they're at least honest enough to not pretend to be unbiased.
ALL news is biased. If they do not engage in bias in the way they report, they most certainly do in WHAT they report.
Bush was excoriated for Katrina. Obama still hasn't responded to the Nashville flooding... but not a peep from his fans in the supposed mainstream media.
Remember the daily body counts from the Middle East when Bush was in office? Where did those go? Remember the questions of Bush's "gravitas"? They're just now beginning to question Obama's response to the oil spill after 53 days.
The greatest bias isn't how things are reported... it is in what the editors choose to report.