See, you've fallen in the equivalency trap.
It has nothing to do with "how far" left or right you are, that's an ambiguous, impossible to substantiate issue.
It has to do with your approach to issues. If you can find a tenth of the cases of Olbermann completely making things up, or tenaciously asserting long discredited lies like O'Reilly does on a regular basis, you'll have an argument.
Please, I'm inviting you to support that claim. To begin, I will submit the recent situation where O'Reilly sent a producer to track a woman down and shove a microphone in her face. Not only was the act itself something that Olbermann has never done, but O'Reilly blatantly lied about both the event's prelude and its aftermath:
http://thinkprogress.org/2009/03/23/oreilly-ambush/
That is by the woman who was harassed.
As for the other people listed, Chomsky, Amy Goodman, these people are leftists, but they approach issues ethically and reasonably. I would love to see someone come up with a quote by a major figure of the left that anywhere approaches the nuttiness of this:
http://www.videosift.com/video/Glen-Beck-thinks-Obama-has-built-FEMA-camps-for-republicans
The awesome starts around 2min.
Again, the challenge isn't that there aren't similarly nutty people on the left, there are, I gave 9-11 troothers as an example because they approach topics with the same nutty, fact-free nonsense as Beck, O'reilly, Hannity, and Limbaugh, but you have to show that these people are given significant air time on major networks.
Remember, congressmen, senators, and other leaders of the right regularly appear on Beck's show, find me the left-leaning correlate.