I've been quite satisfied with university-level US history, or at least what is available in the university I attend. It is quite a sobering contrast to the garbage that is taught in high school (which is not only biased, but incomplete in many ways).
BUT...
High school US history is not inaccurate in the way many of you posters believe it is (though it is understandable you might make those assumptions based on what you know about US culture, and our WW2/Cold War triumphalism). High school history is awful, but in different ways. In high school...
World War 2 is barely mentioned. It gets about 5 pages in textbooks, and wars in general don't get much attention. World War 1 gets about the same attention. The US' "we saved the world twice in two world wars" attitude comes more from movies and games.
History apparently ends around the Vietnam War. Maybe it's because the AP exams don't have post-Vietnam questions, so teachers feel they can just skip everything after. The Vietnam War itself has almost nothing taught about it, though my textbook amusingly blamed the South Vietnamese for losing the war.
Almost nothing is taught about the Cold War. It's not a bias here; there's as little about the "good" things (reconstruction of Germany/Japan, Marshall Plan, etc) as there is about the "bad" things (Vietnam, Guatemala, Iran, Cuba, Congo, Chile, etc etc). They just don't teach shit about it.
So, US history is criminally incomplete when taught in high school. Where I feel the BIAS comes in is the turn-of-the-century history (19th -> 20th), where high school teachers happily neglect to teach anything about the Philippines or Cuba occupations (you think water-boarding prisoners is bad? Check out the water torture US marines used on Filipino POWs), or our hand in the Panamanian Revolution. The rush into China and Open Door is also neglected, as are Woodrow Wilson's punitive invasions of Mexico. And of course American Revolution history is pretty biased, but I guess one can expect that because it's our founding story or w/e. They do, however, teach about how we wiped out the native Americans and how that wasn't very nice.
Also, my teacher hilariously tried to defend the Monroe Doctrine as protecting our neighbors from European meddling, but I don't think that's a general trend among US history teachers here.
So yes, US history is biased in high school. But no, not in the way you might assume it would be. Also, university level history in the US does fill in the gaps and clear the biases.