I love the Apocalypse Genre and i think that atomic annihilation is probably my favourite. (It seems to have fallen out of favour a little over recent times.) I've recently developed a soft spot for the Zombie Genre, which i think can be considered the end of the world.
Personal favourites are probably Stephen King's The Stand and
Robert R. McCammon's Swan Song. I have A Canticle for Leibowitz which i want to read some time this year. (Was Babylon 5's "Deconstruction for Falling Stars" based on this book?)
I read I Am Legend a couple of years ago, which i enjoyed immensely. I also really really enjoyed The Omega Man and I Am Legend movies.
I've not read McCormac's The Road, or seen the movie. I suspect it might be a little too bleak for me.
Stake Land and The Day were a couple of decent post apocalyse movies that were pretty interesting.
I think the end of the world is a wonderful game theme, too. Half-Life II had a pretty decent post apocalytic theme. Apparently, we were supposed to see the Combine taking resources such as water, but it was removed from the game for some reason. I started Fallout, but didn't get too far. I should try it again, really as i love the tone and the design in it. I loved Days Gone, which had an apocalyptic theme to it. (Not quite zombie, but close enough.)