Avatar The Legend Of Korra is by far my favourite tv show of all time, this amazing show is the leader of radical change in children's television, dealing subjects that are hardly talked about in kids shows like racism, genocide, slavery, suicide and homosexuality, making TLOK a sorta, how do you say, a television rebel.
Also, the entire book is animated by Studio Mir, and it is absolutely beautiful, I especially love the scenes in Zao Fu.
Overall, absolutely perfect.