Haven't seen it? WATCH IT.
The link above will get you to the first two episodes. All you have to do is click the red button, then the green button, and then it will start.
Have seen it? It pretty much delivered on all fronts: animation, voice acting, fighting, story, comraderie, relationships, and character development. I haven't been this excited about a cartoon in a long time. I could go on about it... but I don't think the description box is big enough. Also in other news, if you haven't seen, check out the new Legend of Korra trailer below on youtube.
This year and next year are gearing up to be one of the best years for cartoons in a long time. cheers! Be excited, and support your fandoms... Whichever one they are. XD