After reading "One Second After" my interest in survival/end of the world type books was lit.
My brother's partner lent me his copy of "The Road" by Cormac McCarthy. It's a quick read (and I really need to pop it into the post and get it sent back to him!); very dark, yet compelling. I don't recommend it to those who are easily depressed or daunted by a grim view of a possible future.
Next on my list is "Alas, Babylon" by Pat Frank. Published in 1959, the author's viewpoint is firmly entrenched in the cold war but still offers up a gripping story that is well-written and difficult to set down. Read it.
"Lucifer's Hammer" by Larry Niven and Jerry Pournelle is a slow starter; in fact, they spend so much time setting the scene and introducing all the characters, that a reader could skip the first two hundred pages and not miss much. The next 440 pages move along at a good clip and are worth your time. The book does a good job illustrating why expecting plans, even well-thought out plans, to go as expected is a mistake.
When I saw "Fall of Angels" by L.E. Modesitt, Jr. on a recommended list I had to smile; I have ALL of Modesitt's books. My favorites are the Ecolitan series, but the Recluse books are also very good. Regarding this particular book, yes, it follows a high-tech group forced to adapt to a hostile life in low-tech conditions, but probably isn't all that helpful for an actual survival situation. Recommended for it's entertainment value.