I've always liked The Road a lot simply for the fact that you never really get to know why the apocalypse has occurred- it could be anything from nuclear war to ecological collapse or even an asteroid impact is hinted at- even the sun dying isn't out of the question. It's that ambiguity about it that says 'if the world as we know it really ended violently, would anyone know why? Does it matter?
The Road also takes a more unique look at the apocalypse by setting the story the best part of a decade after the event itself, whatever it is. It's set at the point where there's literally nothing left to speak of and humans have totally given up on society of any kind. It's an interesting scenario.