I can't go past a good post-apocalypse tale, from reading Z is for Zachariah (I remember very little of this book, other than it was terrifying, and I keep mixing up parts of the story with "My Side of the Mountain" which isn't even remotely related) back when I was a pre-teen, the Tripod stories a little later (loved loved loved those!), through recent hits such as The Passage (which I didn't like that much) or World War Z (which I did, a lot).
Abe Books has some really great reading lists, and because they're a used book store they tend not to focus on the latest and greatest. And as they pointed out, end of the world or apocalyptic tales are some of our oldest, the story of Noah and the Ark, and similar tales of great floods being something of an ur-example. It's also got some rather unusual examples, including one (The Slynx) which is Russian and i've never heard of it before. And you'd think depressing post-apocalyptic stories would have the Russians all over them. It's in roughly chronological order too, which is nice, I thought.
Any I made a reading list of the excellent Abe end of the world list, in case anyone else would like to give it a shot too.
The original Abe list, including a nice little synopsis of each book: http://www.abebooks.com/books/apocalypse-end-world-armageddon/post-apocalyptic-fiction.shtml