Meaning (Viktor Frankl). Capitalism and Freedom (Friedman). Roots. Hitchhiker's Guide to the Galaxy. Harry Potter. Stephen King.
There are others that are close to the 50 year mark for some of their later work. Heinlein, Asimov, Dune. Tolkein. C.S. Lewis. 2001 Space Oddesey. Charlotte's Web. Watership Down. Dr. Seuss. Where the Wild things Are.