*not to imply PBS/NPR isnt slightly bias
If you hold a certain set of opinions then NPR/PBS doesn't "challenge" you much at all. I'm generally a lefty but I started reading libertarian slanted articles and I have to admit they've got some interesting points of view on things that I hadn't considered before - that's the sort of challenge you want. If you want to be challenged, look to the other side of the spectrum.
The BBC definitely has a political bias and I certainly wouldn't rely on it and swallow their coverage, or more often lack of coverage, like my parents would anymore than I would RT but not being puppets of advertisers gives a different view that the US lacks given that NPR is almost a token service that is kept subdued and out of the view of those who don't specifically go to it and is seen as boring instead of hard hitting journalism.
I like free speech advocates on both sides. YouTube has Dave Rubin, Steven Crowder, Sam Seeder and others and the types of guests they have provide a larger view of things. I wish there were more with a less US centric view but the libertarian scene seems much stronger in the US, maybe as a reaction to all the crap.