A good book is a good book, the target audience doesn't matter. I would even say good children's books and young adult books bear rereading from time to time as you "grow up." You get different things from them at different points in your life.
Fight Club
Yeah, you've seen the movie, and if you are female, this loses half its appeal, and you can go cry about no Brad Pitt, and how Jack is an infinitely better name than Joe.
Hey!! I thought the book was pretty great, and I didn't think Brad Pitt was that awesome in the movie... But maybe I'm just crying 'cause I'm about to get my period or something, I'll go buy some shoes to make myself feel better.
Anyway, back to topic... It's hard for me to say "of all time" but these are the first four that jumped into my head.
The Demolished Man by Alfred Bester
Winner of the first-ever Hugo Award. Takes place in the near future where telepaths are common and integrated into all levels of society. Then the first premeditated murder in decades happens. The book alternates perspectives between the detective and the murderer (who himself is being hunted by a third party), and not in a half-done way -- you know everything about both men from the beginning, the mystery comes from the things that
neither of them know. It was written in the 50s, so it has some decidedly non-PC stuff in it, but it's both a fun science fiction book and a smart detective story.
East of Eden by John Steinbeck
No, really, not EVERYTHING Steinbeck writes is depressing!
East of Eden actually has both sad AND happy parts!* The book has it all -- love, hate, sex, violence, revenge, forgiveness, hope, dreams, family drama, and probably a few other things in a story about... well, it's hard to say what it's about. It's huge (602 pages) and it's about people. It starts with a handful of them and follows their lives and their choices, and the meanings of their lives and choices. Look, I'm doing a terrible job describing it, but if you want a realistic and beautifully written American epic, grab this book.
* Note to folks outside the U.S.: A lot of Americans have to read Steinbeck's
The Grapes of Wrath in high school. It's a good book and an accurate picture of its era, but it also does a great job putting people off Steinbeck forever because it's horribly depressing.
We by Evgeny Zamyatin
Takes place in a dystopian world where life is governed by rules of absolute efficiency, and follows an engineer as he begins to fall prey to emotions that he has always believed are pointless and meaningless. The book was snuck out of the USSR, published in Czechoslovakia, and then filtered westward where it influenced Orwell, Huxley, Rand, and Le Guin.
His Dark Materials trilogy by Philip Pullman
The books are
Northern Lights (inexplicably renamed
The Golden Compass in America),
The Subtle Knife, and
The Amber Spyglass. The setting is a sort of parallel world to ours, with twists -- technology isn't as far along, but magic and science and religion all coexist in daily life; there are races other than humans; and everyone has an outward manifestation of their soul, called a daemon. The daemon is tangible, can speak, is as intelligent as you are, and comes in the form of an animal that reflects your personality (children's daemons are shapeshifters until sometime in their teens). It starts off following a tomboyish orphan named Lyra, a ward of Oxford College in England. A playmate suddenly disappears, and she takes it on herself to find him. And the story gets bigger from there, fueled by Lyra's determination to save her friend no matter what.
There's a movie version of the first book, but it suffers from some of the common problems of adapting big books into movies: it tried to keep too much of the book, and it relies too much on exposition. It looks beautiful and the casting is incredible -- but it doesn't make much sense if you haven't read the books, and there's an
awful lot of talking.