While I think Fox News is the least biased of the news agencies, it's nearly impossible to take ALL bias out of the news. It's presented by humans, and thus has bias built-in. Heck, even "statistics/numbers" can be presented to give one side or another.
True, bias can never be completely eliminated. Human nature always gets in the way. However, the idea of being objective in the news has really disappeared. Viewer trust in the news has been in serious decline over the past 10 years, and for good reason.
The main problem with media bias is their ability to skew the story. Most bias is presented by leaving out important facts of a story, or not presenting both sides of the story. By doing this, it skews the viewer's opinion of a particular topic. CNN, MSNBC, Fox News, and others are all very guilty of this practice on almost a daily basis. That's why your suggestion of watching multiple news sources is right on the money. That is the only way to really get the entire story, use objective analysis of all the facts, and then come to your own conclusion.
Just because a person might think a news source is "liberal", doesn't mean that source should be ignored. Often, there is information there that isn't presented by a "conservative" source. And of course, vice-versa.
What needs to happen in news is that these media outlets need to keep their political views in check, and present stories in an objective manner, and stop withholding information from their viewers.