1. Sophie's World by Jostein Gaarder
    Dense, packed with flavor like a heavy bread, and sustaining like lembas.
  2. Small Gods by Terry Pratchett
    Concerning the nature of belief, faith, and religion. Also, I've read most of Pratchett's books more than once.
  3. The River Why by David James Duncan
    Like a direct tap into Young Love, Self-Discovery, Passion, and Things That Are Vital But Ineffable.
  4. My Side of the Mountain by Jean Craighead George
    Probably the most reread book of my youth. Something about getting away from all people and living alone in isolation, learning valuable skills every day, and making the most of the resources available just SPOKE to me.
  5. C.S. Lewis's The Chronicles of Narnia, Robert Asprin's Myth series, Tracy and Laura Hickmans' Dragonlance series, and Piers Anthony's Xanth series
    I read all of these multiple times in high school, not something I'm proud of. I guess it was appropriate for that age, but ...
  6. The Great Brain series by John D Fitzgerald
    Great series that was a snapshot of an age several ages ago. Considered a kid's series but a lot to offer.