Till We Have Faces by C S Lewis will always be one of my favorites. It's a retelling of a Greek tragedy that got totally ignored in modern media. The story follows the life of a princess in ancient times. She's ugly and not ladylike, so everyone - subjects, employees, and her parents - all prefer her sister. But her sister is spirited away to marry a minor god and the main character is left to take care of the kingdom.
The story is told in three parts, all of which are kind of like diary entries. Part one sets up the plot, part two talks about how she handles being queen, and part three is her on her deathbed regretting most of her life decisions. Watching the character grow and face the consequences of her actions isn't something you normally see in a book, and it's even better because it's in first person.
C S Lewis is such a well known author and the book was praised by Tolkien, but for some reason most avid readers haven't even heard of it. If you like stories about psychology or the human condition it's a great read (Although I'd recommend the audiobook if you can get it.)