Main Series:
* Avatar: The Last Airbender (published between 2004-2008)
* This is the original graphic novel series that tells the story of Avatar Aang and his friends as they restore balance to the world.
Spin-offs:
* The Legend of Korra (published between 2012-2014)
* This series takes place 70 years after the events of Avatar: The Last Airbender and focuses on the story of Avatar Korra.
Other:
* There are also several single-issue comics set in the Avatar universe, as well as novels, art books, and other supplementary material that delve deeper into the world and characters.
Let me know if you're interested in learning more about any specific books or series!