I love it, it's amazing. It did have a few weaker episodes, but overall I can easily say this is one of the best anime I've ever seen. Most memorable too. The protagonists were very relatable and easy to root for.

Although the show tried to convince us that "the Avatar team members" were just kids, they all looked and acted at least a few years older, especially Aang (he really doesn't sell a 12-year-old kid, especially in season 2 and 3). But that's a good thing. I liked it better for it. Prince Zuko is another great example. He was supposed to be around 16, but seemed more like 18, if not even 19. Again, I preferred it this way.

Characters' archers were done splendidly. Especially Zuko's. His journey was by far the most transforming and I liked how he struggled to choose between good and evil.

Aang's crush on Katara was cute at first, and I thought nothing of it, but then it has developed into something more, even if it did take a long time for it. Their love was definitely something to root for.

And last but not least, Sokka and Toph. Both were absolutely amazing. One a warrior with a fun side, always saying something funny, but also really looking out for his sister and other friends, and the other a blind girl with unimaginable power. Even animal companions had their own characters. Loved it.

And the finale! It was amazing. One of the best ones in the history of TV shows. "Avatar" really built up to it. Just go see it. I couldn't recommend more.

PS: If you haven't watched yet "The Legend of Korra", which is supposed to be Avatar's sequel, please don't. It destroys everything "The Last Airbender" holds dear. You'll just end up depressed. instead, pretend it doesn't exist. Trust me, it's better this way.