Probably going to have to be The Road by Cormac McCarthy.
It was a difficult book to read. Very slow, very depressing, very dark, very moody. Even still, I could not put it down because the relationship between the Man and the Boy was so wildly compelling. McCarthy's descriptions of the world and daily struggles the two face is beautiful. Haunting and at times disgusting, yes, but beautiful nonetheless.
And hey - screw you, Nicholas Sparks, for saying your writing is far better than McCarthy, Hemmingway, and Shakespeare. You massive butthead. Yeah, I went there. What? That's what I thought. Go staple gun your face to lava, Mr. Cliched Romance Novel, I want none of your pish posh. :|