This is actually a comment to the post below but I wanted to stick in a few links...
The most pant-soilingly scary apocalyptic vision has to be this. You may scoff but if you have a look at the date on the cover you'll see that to a 10 year old boy this was indeed the end of the world. Deadworld, where all life has been declared a crime since only the living commit crimes. I may be 35 now but reading that still gives me the heebeejeebees.
Other apocalyptic visions... I am legend by Richard Matheson and the movie of (apparently a remake is in production with Will Smith as Neville due out next year - cooooool). Mary Shelley had a stab in The Last Man. Wells' Shape of Things to Come is pretty scary and prescient. And I always thought of Waiting for the Barbarians by Coetzee as a pretty apocalyptic novel.
Hard to go past George Miller's excellent Mad Max movies (the first two) and Costner's Waterworld is a grossly under-rated pic. Planet of the Apes, Night of the Living Dead, Texas Chainsaw Massacre, The Terminator films (not pt 3), Kiss Me Deadly (1955, Robert Aldrich - what was in that box?), Soderbergh's re-make of Solaris is pretty bleak, War of the Worlds starts promisingly but has a cop-out ending.
I played a computer game last year called Half-Life 2 which was unbearably apocalyptic and seat-jumpingly scary.
All of which to say is that I'd happily sit through all of the above a dozen times than attempt the new McCarthy. But then again I'd rather chew my own arm off than waste time with his torpid, unpuntuated prose.