From the incredible character development to the constant action and humor, this is just truly the best animated show ever, and in my opinion the best show ever, bar breaking bad. The Gaang are some of the best written characters in fiction who perfectly play off of each other. Dialogue is never dull as there is just an infinite amount of humor to be thrown around. While the first season is admittedly "weaker" than the other two, there is not a bad season in the show. Even the filler episodes seem to further characters and plot. And don't get me started on the season finales. Every season builds so flawlessly up to the finale and is resolved in such an amazing way. With the exception of two or three minor characters used for plot development, there is no character who isn't fully fledged out. Most notably, Zuko, who has imo the best arc in fiction (again, barring maybe Walter White) I can't say enough good things about this show. Everything down to the soundtrack is just *chefs kiss*. Watch this if you haven't, it is so worth it.