I like avatar better:

Avatar for: Action, Adventure, funniness here and there.

Spongebob for: Funniness

I like the twists in Avatar like in the spirit game or whatever it is, they show some of Aangs past lives- (Roku, Kyoshi, Kuruk, and Yangchen)I was sooooo surprised at Avatar Kyoshi's story! Who knew Avatar Kyoshi was the one who created the corrupt and evil Dai Lee? Of course, she thought she was doing it for the better...

And Kuruk seems like an older Aang, especially in the episode "The Warriors of Kyoshi".