Gödel, Escher, Bach: an Eternal Golden Braid -- I keep finding some new ideas for me explore every time I read it (especially given that I re-read it every 7 years or so).

The Hobbit -- it was a gift from a friend in my second or third grade and I'm still drawn to read it from time to time many years later.

The Goal: A Process of Ongoing Improvement -- a well described process improvement progression in the format of a novel. It keeps reminding me that focusing on local optimizations can (and likely will) lower the overall performance of the system.