Scrapped Princess: Oh god. Can I pick everyone? Uhh. I think I love Pacifica the best, and her brattiness and self-worth issues would make her fun to play.
Gargoyles: Puck --Lexington. He'll geek out over technology and hang upside-down from things.
ATLA: Korra because she is going to be so awesome. But if I have to pick a character I can app now, I might go for Toph. She is also awesome and has the bonus of having the most awesome and underloved element of all: earth.