The Road by Cormac McCarthy

A Pulitzer prize winning post apocalyptic story about a man's struggle to keep his son alive. They trek Southwards towards the ocean in a world devastated (presumably) by nuclear winter. Plant and animal life appears to have been virtually wiped out and most of the remaining humans survive through cannibalism. The man and his son see themselves as the good guys and they struggle to scavenge what they need from the decaying remains of human civilisation. Strong stuff and a great read. Might annoy hard line sci fi purists I guess because the scenario in which humans survive while all else is destroyed is not particularly credible but that is not the point of this book.