Neil Gaiman's simply one of the best storytellers in the market right now. Mixing the whimsical and macabre, he uses an uncomplicated story to convey a powerful, understated effect. My dad described his writing thus: "It's like you're walking down an ordinary street and then you take a left turn and there's Faerie." The Graveyard Book is close to my favorite of his novels (Coraline might be the winner), and in it he sets us into a small world with a supernatural twist. Bod is an ordinary boy, raised by ordinary parents, who just happen to be ghosts.
I read My Antonia once before in what was probably Middle School, but I obviously didn't get it. This was the time it finally clicked: the atmosphere, the untamed prairie, the romantic realism of it all. Also, that epilogue was about the most winsome portrait of a huge family that I've ever read.