OK. You have your fortified retreat, your guns, your bullets, your food supplies, your water system, your crank flashlights, your outhouse, a garden in the backyard, an orchard growing in the southern quarter, your fences are up (including the rolls of barbed wire and the signs that tell trespassers how gruesomely they might expect to die). Now what?
Did you forget entertainment? Besides sex and violence, I mean.
Have on hand a supply of books. These come in several types.
1. Interesting technical books that make you feel uplifted and important, assuming you can comprehend the equations.
2. How-To-Do-It-Dummy books that show you how to do things which are useful in survival situations and in low-tech cultures.
3. Historical books that detail how human cultures were led, largely with lies, stupidity and cowardice, and especially during the Era of Petroleum-Fueled Exuberance.
4. Fun fictional novels. Romance (for your girlfriend to get in the mood and stay there). Science fiction for you. Fantasy for you both.
I'd keep the books in the first category to a minimum, unless you can imagine why your children and grandchildren will need to be able to solve the equations of stellar structure for Sirius. These books are primarily to gratify your sense of nostalgia and give you feelings of enjoyment in return for all the money you spent on the wrong education.
The books in the 2nd category will be useful to every generation of your folk, though in time they will become heavily augmented, if not replaced, by practical traditions for farming, animal husbandry, carpentry, brickmaking, building with stone, medicine, having babies, raising children, roofing, trapping/hunting, spying on possible enemies, making and using weapons, war strategy, etc. But in the beginning, everybody will be people who were accustomed to letting institutions and experts do all the thinking and will, therefore, be ignorant and in need of reference material.
In the 3rd category, I could suggest proper historical material, but you wouldn't listen to me. So just pick books that have slants agreeable to you. Enough said.
As to the 4th category, here are my suggestions.
4a. A Song of Ice and Fire. This is a series in progress, with four very lengthy novels and a prequel so far completed, by George R.R. Martin. It's the best fantasy tale I've ever read.
4b. Lyonesse. A trilogy by Jack Vance. It's the next best fantasy tale that I've ever read.
4c. Deverry. A series in progress, by Katharine Kerr, with 14 novels of quite respectable length so far completed.
4d. Farseer. A trilogy by Robin Hobb. It is followed by a pair of sequel trilogies, which you might also want to procure: nine large volumes in all.
4e. Earth's Children. A speculative history fantasy series about people living during the last Ice Age, about 25000 years ago, by Jean M. Auel. The predominant religion seems to be about nature and fertility, so there are quite a few graphic sex scenes scattered through most of the books.
4f. Riftwar Saga, as well as subsequent/related series, by Raymond E. Feist. Swashbuckling adventure fantasy of very good quality.
4g. These books by Robert Heinlein: The Rolling Stones, Methuselah's Children, The Moon is a Harsh Mistress, Time Enough For Love, Starship Troopers, The Number of the Beast, The Cat Who Walked through Walls, To Sail Beyond the Sunset.
4h. Darwath, a series by Barbara Hambly. Semi-horror fantasy about what can happen if invading monsters aren't stopped soon enough.
4i. Dune, a series by Frank Herbert, involving a harsh desert environment, limited resources, and religious fanaticism.
4j. Battlefield Earth, by L. Ron Hubbard. A very lengthy book about a hero who leads his people in war against an alien occupation, and then saves the world again from a gang of galactic bankers!
4k. The Wheel of Time, by Robert Jordan. Great fantasy with lots of political intrigue. Eleven very long books and a medium sized prequel have been published. The author died before issuing the final volume, but this is now being written (from Jordan's notes) by another able storywriter and should be published soon.
4l. The Lord of the Rings, by J.R.R. Tolkien, the man who began the return of high fantasy in modern times. He's a master of magical atmosphere, the kind where a rumble of thunder in the distance has a profound philosophical meaning that you can just barely sense (but can't quite understand).
4m. The Saga of Recluce, by L.E. Modesitt, Jr. The usual form of this 13 (going on 15) volume series is "young boy goes out into the world and makes something of himself," and, by the way, there are powerful people who want to kill him and probably would have if it hadn't been for the warning and/or help of his brave girlfriend.
4n. Mars, a trilogy about interplanetary colonization by Kim Stanley Robinson. It's a pastoral tale about what mankind might have done if he had more correctly invested the terrestrial supply of fossil fuels. Consider it an alternative history, a might-have-been, to teach your youngsters how dangerous it is to let fools (like our leaders in the real world) have power.
4o. FORGOTTEN REALMS is a universe containing several different series, the best of which are by Ed Greenwood (Elminster), R.A. Salvatore (Drizzt do'Urden), and Elaine Cunningham. Mostly easy reading, but there are some moral lessons to be found.
4p. These books by Clifford D. Simak: The Goblin Reservation, Project Pope. Most of his other books are also excellent, but these two will give you the flavor.
4q. Memory, Sorrow, and Thorn, a series by Tad Williams comprised of four volumes, the first two being of moderate length, the other two considerably longer.
I'm presently on a tour of modern fantasy literature. Or, rather, I will return to that tour after I've finished William R. Catton's OVERSHOOT, the Ecological Basis of Revolutionary Change. So if I think about it, I might return to this post and lengthen it some. There are many series that I suspect are also quite good, but I haven't had time to read them yet.