Apocalyptica

So I just finished Orwell's 1984 a few weeks ago, and I'm feeling a growing melancholy. Anyone have good suggestions for end-of-the-world-scenario novels, or post-apocalyptica? I've read SK's Dark Tower series, and while not perfect, it did capture that sense of despair I am currently feeling.

Do Androids Dream of Electric Sheep- Philip K. Dick;  World War Z- Max Brooks; I am Legend- Richard Matheson.

http://en.wikipedia.org/wiki/List_of_apocalyptic_and_post-apocalyptic_fiction