It's a pleasure to read your passionate reviews of the literature you treasure. I wanted a reference to Taoism, so I ordered the Tao Te Ching translated by Ursula K. Le Guin.
The books I've returned to most often are Gertrude and Siddhartha by Hesse, The Foundation Series by Asminov, and a volume of The Works of Edgar Allan Poe, given to me by my 10th-grade English teacher.