Zuko's character development is so good you can feel his pain... I almost cried for him (no homo)Sokka & Zuko.
Sokka's sense of humor and interaction with other characters is just priceless. Originally I didn't think much of Zuko in the beginning as he just looked like a skinhead, but along the way I started to like him more and more. He's probably one of the better drastic character developments I've ever seen.