Avatar: The Last Airbender
Book 3: Fire
I will say right now that I'm going to be biased about this season of Avatar: The Last Airbender, because "Book 3: Fire" is my absolute FAVORITE of the entire AtLA and Legend of Korra franchise. "Book 3" is the culmination of Team Avatar's adventures, their struggles against those seeking to end the world, and their constant character growth.
Let's get to the nitty gritty. (And, keep in mind, there WILL be spoilers this late into the season.)
"Book 3" continues from "Book 1: Water" and "Book 2: Earth," with the Avatar and his gang still fighting the good fight against the notoriously powerful Fire Lord, Ozai. "Book 2" ended in quite the bleak cliffhanger: Zuko betrays his uncle in order to win favor with his father, Ozai, Azula "kills" the Avatar in his Avatar State and takes over the Dai Li and Earth Kingdom in one fell swoop.
Through the ministrations of Katara's healing skill (and spirit water), Aang revives from his mortal doom, only to find himself on a Fire Nation ship, dressed in Fire Nation clothes, and with a head full of hair. After his initial shocked reaction, it is revealed that the vessel is merely a guise taken on by the Water Tribe and a multitude of rebels attempting to escape the Fire Nation's detection. It is also where Team Avatar is hiding away, since the world still believes the Avatar is dead. With the hope that the Water Tribe can take the Fire Nation by surprise (during the Day of Black Sun), Aang and his team make it to the Fire Nation with one goal in mind: to see Aang finish his Avatar training once and for all and master the final element in his arsenal.
It is not so easy to learn firebending, however. The Fire Nation is a hostile territory, and, even disguised, it is difficult for Aang and his friends to shake off their non-Fire Nation mannerisms. Additionally, without a firebending instructor, Aang's hope of mastering the element is near impossible, especially when his very nature is against using firebending for harm.
Each episode brings with it an interesting aspect about the Fire Nation and its people, and even more insight into many characters. Sokka finds himself a sword master to hone his fighting craft ("Sokka's Master"). Toph's continual bouts of rebellion are tempered slightly by the friends around her ("The Runaway"). Katara discovers more dangerous forms of waterbending ("The Puppetmaster"). Aang and Zuko learn that they share an interesting past ("The Avatar and the Fire Lord"). Heck, there is even some insight into Azula, Mai, and Ty Lee ("The Beach"). And this is all gathered from the FIRST HALF of the season.
While each of the previous episodes is pretty much fantastic, it is the latter half of "Book 3"--starting with the two-parter, "The Day of Black Sun"--that has me raving like a fangirly fangirl. A lot of things have gone down at this point: the allied Water and Earth nation troops attack the Fire Nation capital, the solar eclipse prevents firebenders from using their bending abilities, Team Avatar joins in on finding Ozai and getting rid of him once and for all, and Zuko undergoes the final leg of his hero's journey.
I will tell you now that past the halfway point, all episodes just keep getting better and better. Zuko finally joins Team Avatar as the long sought-after firebending master for Aang. For those who'd been following my reviews of this series, you'd probably be able to tell that Zuko--and, really, many of the Fire Nation denizens--is my favorite character. It could probably explain why Team Avatar "post-Zuko" saw many of my favorite episodes to date ("The Western Air Temple," "The Firebending Masters" and the "The Boiling Rock" two-parter are prime examples). This bias notwithstanding, the last episodes brought past storylines back and tied up many loose ends, and much of the two-hour finale--"Sozin's Comet"--was filled with truly epic battle scenes.
"Book 3: Fire" raged on like its elemental namesake and burned brightly throughout the season, its climax a fantastic, crackling bang, its ending a victorious display of the world at the end of its Hundred-Year War.