Aang may have been the last airbender, but he wasn't the first Avatar. A new Avatar reincarnates in every generation, and over the course of thousands of years there were quite a few generations. Aang or Korra may be your favorite Avatar, but which one before them was the best?
To figure this out, we need to look at their history, personality, powerset and accomplishments to really evaluate where the past Avatars stand in relation to one another. With everything we know from the original series, the sequel The Legend of Korra, the comics and the new Kyoshi novels, there's a whole lot about every Avatar to lay out. They each have their strengths, but only one can be the best.
Unnamed Avatars
There are hundreds of Avatars fans have yet to learn the names of but there are scraps of information here and there to gather about them. What helps bolster the ranking of the unnamed Avatars is not necessarily in what they have done, but what they could do. There's still so much unexplored story potential in the lives of the past Avatars.
According to a tweet by author F.C. Yee, fans will learn more about the past Avatars in the upcoming The Shadow of Kyoshi novel and even learn the name of the Fire Avatar who erupted four volcanoes in a vision of Aang's.
Wan
Although the legend of Wan served as one of the best self-contained stories in either of the Avatar series, it's a little hard to doubt that Wan himself was far from the best Avatar. Credit where it's due, Wan revolutionized how bending worked in his era and started the line of succession that created the Avatar. He made major strides in diplomacy between the spirits and the humans... but were they strides in the right direction?
Little is known about the rest of the world beyond Wan's civilization but unleashing the powerful spirit of darkness, Vaatu on the world can hardly be said to be a good thing. Granted, Wan fused with the spirit of light, Raava, to help balance the scales, but they wouldn't need balancing if Wan hadn't come along in the first place. What's more, his banishment of the spirits from the human world and closing off the spirit portals became a forgotten mistake that wouldn't be corrected until the time of Korra.
Roku
Perhaps the past Avatar seen the most in the original series was Aang's immediate predecessor, Roku. Born of the Fire Nation and a well of good advice for Aang while he learned the ropes of the Avatarhood, Roku was a towering and imposing force. With his personal dragon Fang attending him in the Spirit World, it's hard to look at Roku and imagine there was room for weakness or mistakes.
However, much of the plot of Avatar: The Last Airbender concerns itself with the 100 Year War Roku himself is partially responsible for. Roku allowed his friendship with Fire Lord Sozin to interfere with his responsibilities to maintaining harmony in the world, and when he had foreknowledge of Sozin's planned takeover of the globe he did too little to prevent it. However understandable the mistake may be, there's no doubt that it was indeed a mistake that mars Roku's legacy more than any accomplishment we can weigh against it.
Yangchen
Though little is known about Yangchen's life from the main television series itself, the comics and novels help shed further light on just who the Air Nation Avatar was. The Rise of Kyoshi shows that in the century following Yangchen's death, her legacy was one of success and virtue. Known as a student of philosophy who studied the Guru Laghima, the comic book The Promise also revealed Yangchen's history with General Old Iron in defending a small village from the spirit's wrath.
But there seems to be something darker lurking beneath the surface. Yangchen told Aang herself to prioritize his role as the Avatar over his teachings as an Air Nomad, even if it meant discarding his pacifism. Any fans who recognize the Guru Laghima's name know just how dark his teachings can get, as the villainous Zaheer from The Legend of Korra embraces Laghima's ethos following the death of P'Li. We may learn more about Yangchen in The Shadow of Kyoshi novel, and it may not all be good.
Kuruk
Another Avatar whose reputation has been fleshed out in the novels is Kuruk, the Water Tribe Avatar previous to Korra. Aang saw him briefly in a vision bending a tidal wave he surfed along, and Aang even met him in Escape to the Spirit World where he learned of Kuruk's lost love, Ummi. It seems that the evil spirit Koh the Face Stealer held animosity toward Kuruk, and even during Aang's life, Kuruk continues a search to reunite with his love.
During Kyoshi's time, her predecessor's reputation was one of revelry and mighty deeds. Said mighty deeds seemed to have more to do with arrogant challenges of his ability, but his era was still known for its far-reaching peace and prosperity. Kuruk's "go with the flow" attitude, fascinating life traveling the globe to challenge the best of the world and heart-wrenching tale of a life extinguished too early makes ranks him as one of the best Avatars in history. But not THE best.
Kyoshi
The title of best Avatar can only go to Kyoshi, Roku's Earth Kingdom predecessor whose legend loomed even over Aang. Kyoshi broke records as the Avatar with the longest reign (living over 230 years) and the largest feet, created the Kyoshi Warriors and the very island they call home, and even founded the Dai Li in order to better protect the heritage and history of the Earth Kingdom. As an Avatar it's clear she was one of the all-time greats, and her books make it clear that there was a human wrapped up in all that greatness as well.
The Rise of Kyoshi opens on a time before the Avatar knew she was the Avatar, and catalogs her quest to self-discovery and confidence in mastering the four elements. All of the trappings that go with Kyoshi, including her costume and war fans, make her feel almost more like a superhero than any other Avatar. She even became an LGBTQ+ icon as a bisexual woman who defended non-hetero couplings throughout the infamously conservative Earth Kingdom. You just can't get more interesting, inspiring or powerful than Kyoshi.
The Shadow of Kyoshi, by author F. C. Yee, is the sequel to Yee's previous novel The Rise of Kyoshi. It will be released on July 21 and is currently available for pre-order.