Both "The Last Airbender" and "Legend of Korra" might be amongst my favourite animated series. It is a clever, fun and entertaining series with some great character developments and an interesting universe. I think that "Legend Of Korra" is a little too busy sometimes and often skip important background stuff very easily, but on the other hand I really appreciate the level of animation and general craftmanship put into this series. "The last Airbender" has great characters and a great story and I always enjoy watching it.
Well enough writing, great series that's all I wanted to say :)