Lila

I'm 28 and I've read it 3-4 times now. It's a truly an inspired work. I think that it would appeal to the HN community because the author, Robert Persig, arguably reaches a statement of enlightenment entirely through deductive reasoning. The story is essentially Persig's attempt to piece this whole event together after having undergone electric shock therapy. The story unfolds as Persig and his son travel across the US by motorcycle and is complemented by intermediary "chautauquas" (philosophical monologues) and technical monologues about motorcycle maintenance. The book is an enigma (unlike its sequel "Lila" which is not), and there isn't any other book that I've read that is like it.

Best overall: Zen and the Art of Motorcycle Maintenance, and its less well-known sequel, Lila Best fantasy in terms of most imaginative and full of wonder: The Neverending Story by Michael Ende. (I know, everyone saw the crappy movie; it simply does not do the book justice.) Best Scifi: The Hyperion Cantos by Dan Simmons