Aang
Aang, in "The Storm" (the 12th episode of first season), said that he wishes he had been there to help Air Nomads a century ago, but would rather live a child's carefree life. Many times in the show, Aang shows how much he cares for those are close to him. He also showed that he can act immaturely, and once tried to deceive others in order to keep the group together. In "Bato of the Water Tribe" (the 15th episode of first season), Aang thinks Katara and Sokka might leave to visit their father. Aang hides the map showing their father's whereabouts and lies about having it in the first place.