Good choices. I'll echo the Iroh and Zuko picks and throw Aang and Toph into the mix. The supporting cast is so strong that it's easy to forget about the main character himself but I really like the path Aang takes in finding a way to defeat Fire Lord Ozai without taking his life. It shows how he respects the peaceful legacy of the Air Benders. As for Toph, she's a total badass. I love that tournament where she's introduced, and then her creation of metal bending has some huge effects on the world of Avatar. I also think she's cute when she's together with Sokka.