Avatar: The Last Airbender aired for three years in the mid-2000's.
Avatar : The Last Airbender ( Avatar : The Legend of Aang in some regions ) is an American animated television series that aired for three seasons ( referred to as `` books '' in each episode 's title card ) on Nickelodeon from 2005 to 2008 . The pilot episode first aired on February 21 , 2005 , and the series concluded with a widely praised two-hour episode on July 19 , 2008 .