Heroes of Olympus:
Percy Jackson: 17
Annabeth Chase:17
Piper McLean: 16
Jason Grace: 16
Frank Zhang: 15
Hazel Levesque: 13
The Harry Potter Series:
Harry Potter: 17
Ron Weasley: 17
Hermione Granger: 17
The Underland Chronicles:
Gregor: 13
Luxa: 13
Star Wars Saga:
Supreme Commander Patrick (made up, but my overall favorite)
Jessica, (you will have to read to see who that is. :)