My favorite character in The Outsiders is Darrel Curtis. In the aftermath of the death of his parents, he has stepped up for his younger brothers, Ponyboy and Sodapop, in ways that not many 20 year old men would. He has forgone the opportunity to go to college on a football scholarship, despite having both the sporting ability and the brains to have excelled in this environment, in favor of working two jobs to keep him and his brothers together.
Despite the fact that he has many conflicts with Pony, it is evident that he cares a great deal about his brothers. When he is tough on Ponyboy, it only because he loves his brother and does not want him to get hurt. He is both strong willed and in possession of the serious nature required to hold the family together. He takes on just about all the housework and cooking and takes responsibility for his orphaned minor brothers in every way possible.
In spite of his current circumstances, it seems very clear that Darry will achieve something with his life. Despite being a Greaser, he has Soc-like characteristics, such as a clean-cut appearance, and fights only to showcase his athletic stature rather than for the sake of violence.
Darry is little more than a boy himself, yet he has been thrust into a man's role, and I would argue that he does a more admirable job than most people his age would have.