Help!!

We're purchasing a Kindle for my gifted ds 13th birthday and I'd like to pre-load it with a few books. I'm at a point, though, where I'm having trouble finding appropriate books.

Here's what's out: Anything from the kid's section, anything "heartwarming" or with an unrealistically happy ending, typical teen garbage fiction, vampires, female boy-crazy protagonists, anything written over 100 years ago, graphic descriptions of, ahem, Adult behavior.

He's interested in adult books now, but nothing that has MA content that would make him or I squirm. He's fully in the throes of teenage angst and existentialism, so he needs thoughtful stories. A few books that meet his requirements and that he's already read and enjoyed: Life of Pi, Peace Like a River, The Curious Incident of the Dog in the Nighttime, Into the Wild.

Does anybody have other suggestions?

TIA!!

Kitty