Oh, and for those who don't know it yet, Legend of Korra is back!
For those who don't know what I'm talking about, LoK is the spin-off of Avatar: the Last Airbender. If you've accidentally watched the movie, go scrub your eyes with bleach and watch the series, like you should.
The Last Airbender is a fairly childish series, especially in the beginning. However, it gets heavier and more serious as you advance into the later series. Plus bonus Mark Hamill as evil overlord!
Legend of Korra is a bit more... adult. Sure, it still has some funny moments and comic reliefs almost every 20 seconds, but the plot is more advanced, the scenes are darker, and the ending of the first season? Jeez, not exactly child friendly.
Just go watch it, it's one of the best cartoons I've seen.