After a bunch of recommendations, I read The Hunger Games trilogy. These are Young Adult books, and they are violent, bloody, disturbing … and also impossible to put down.
The books really are pretty brutal. They make the deaths in Harry Potter look light by comparison, and the Hunger Games heroine Katniss makes Twilight's Bella Swan look pretty weak too.
But it's framed in such a way that it pulls you in rather than drives you away, which is an impressive feat considering the subject matter. And the author lets her characters wrestle with the morality surrounding the violence.
I don't know how I would feel about giving these books to a kid, but they're a pretty good read for an adult. The third book is probably the weakest, with I and II being the best, but that is probably only in its relation to the first two, which are very strong.