There are a few books that I read over and over again. One of these is Alas, Babylon by Pat Frank.
I first read it while in Junior High School, which you have to remember was during the 70s so war with Russia was a very real possibility, at least in our minds.
The Amazon description of Alas, Babylon is:
"Those fateful words (Alas, Babylon) heralded the end. When the unthinkable nightmare of nuclear holocaust ravaged the United States, it was instant death for tens of millions of people; for survivors, it was a nightmare of hunger, sickness, and brutality. Overnight, a thousand years of civilization were stripped away. But for one small Florida town, spared against all the odds, the struggle was just beginning, as men and women of all ages and races found the courage to join together and push against the darkness."
The book is short. Amazon lists it at 352 pages but I can only assume that is some version with some type of fluff added in since the book is easily read in a day or two by a casual reader and less than a day by an avid one.
Although dated in many ways, the original year of publishing was 1959, the characters in the book still ring true and it does a good job of pointing out ways people find to cope and survive in a disaster.
I would rank Alas, Babylon in my top ten books and it should still be required reading in all high schools. To show how much I think of it I actually have several copies around the house, purchasing a new one every time I couldn't find a copy here, and recently bought it again on Kindle so it would be available whenever I got the urge to leap back into it.
While I realize a book about a nuclear war in 1959 isn't as sexily terrifying as some of the Apoc-lit or Zombie Apocalypse (Zompoc) books that are out now, to those of us who wtill remember the duck and cover drills the potential for a man-made nuclear disaster is still real and just as terrifying as the walking dead.