Not really a news source, more like a collection of articles from everywhere, but I get some of my news tidbits from digg.com.
You can get some interesting articles from Digg (I visit it too for that reason) but I think you probably shouldn't look at the comments. Their comment system is broken, which means you either get whole pages worth of either sour conservatism, cynical libertarianism or Obamania. Most of the people who post there are either complete idiots or simply very happy to not have to think very much.
huffingtonpost, thinkprogress, and def. keith olbermann are basically just cheerleaders for the american democratic party
Does that matter very much? I know very little about American media (since we don't get a lot of it and I picked up other stuff online) but from what I can tell there's a surprisingly small amount of good news resources that don't portend to this. Those that do are usually very boring. Stories that are explained from a POV usually tend to be a bit more explanative as well. There's nothing wrong in reading a site like The Huffington Post and accepting that they too are omitting or sensationalizing things for the sake of their viewpoint; as long as you know they are, and that viewpoint does not make you sick to your stomach.
No matter what you read, whether it's The Huffington Post or the NRC Handelsblad or politically oriented semi-entertainment like Keith Olbermann, you have to be on your toes anyway. I'd rather read any of the former than Drudge Report.