1. At first I had a soft spot for Katara, but by the end Prince Zuko was my favorite.
2. I wish we'd learned Yue's moon backstory a little sooner. Maybe in the penultimate episode, in a scene where she was bonding with Sokka? It was all a little too quickly for me.
3. I wonder if Aang is really the last airbender, and if so if we'll get an explanation as to why the airbenders were so thoroughly eliminated while water and earth survived.
4. Overall, it was excellent as I expected it to be from what I've heard of it.
Please don't spoil me for upcoming episodes!