The Cider House Rules
By John Irving

This novel is about a boy named Homer who grows up in an orphanage in Maine—and how he leaves it for the larger world. But I was more fascinated by the character of Dr. Larch, the director of the orphanage. He's so dedicated to these kids—you think he's a saint—but then you discover he's an addict. And this discovery presents the idea that no one is perfect, and a person can still be good and noble despite his faults. His addiction humanized him.