Retrospective-Avatar: the Airbender Book 1, Chapter 9-The Waterbending Scroll
For the longest time I did not like this episode. Mostly because of the A plot. It pissed me off that Katara, who has been a waterbender for years, is showed up by Aang in his first lesson. But then, as I watched in again, I realized that was the point. You're supposed to me mad like Katara is, because it does suck when you introduce a friend to something you take pride in being good at and they quickly become better than you. It happens in real life, and is just as upsetting. It also makes sense, Aang is a natural at it because he's already learned it hundreds of times before. It also makes it so much sweeter later when Katara's hard work and practice kick Aang's natural talent in the ass.
The B plot is a lot of fun. Iroh and Zuko both get great lines, and it adds to their already great characters. The episode has very above-average action at this point in the show. There are several fight scenes, and each is creative and interesting. I also really like the pirates, and how they're not just the average Anglo-Saxon pirates we're used to. Overall, it is a very good episode.