Because you like Virginia Woolf in The Hours
Daria Morgendorffer is so defensive that she actively works to make people dislike her so that she don't feel bad when they do. See them in Daria.
Buttercup is a farm girl turned princess who'd do anything to have her old life back. See them in The Princess Bride.
While Fantine's gentleness has led others to take advantage of her, it ultimately forces her to become stronger. See them in Les Miserables.
Juno MacGuff is hoping sarcasm will get her through the stress of teenage life. And also, teenage pregnancy. See them in Juno.
Walter White's knowledge of chemistry allows him to cook astoundingly pure meth, leading to a rapid – albeit tumultuous – rise in the criminal drug world. See them in Breaking Bad.
Alison DiLaurentis believes you're always better off with a really good lie. See them in Pretty Little Liars.
Leslie Knope can accomplish anything, literally anything, with a little grit and help from her office. See them in Parks and Recreation.
High school is Hell, so Allison Reynolds spends her time giving herself tattoos with ballpoint pens and shaking dandruff out of her hair. See them in The Breakfast Club.
Once a lonely hat maker, Sophie Hatter is now cleaning goo from bathtubs and cooking breakfast for the grumpiest wizard in all the land. See them in Howl's Moving Castle.
Usagi Tsukino may look like a lazy teen, but when Usagi conjures up her alter ego and calls her Sailor Scout team, no villain stands a chance. See them in Sailor Moon.
With his own ship, Peter Quill calls his own shots, and gets to fly from planet to planet blasting '70s pop hits and picking up alien chicks. See them in Marvel Cinematic Universe.