My List goes something like this:
(It is not fixed, or exclusive, and is liable to change over the medium to long term, but is in some rough semblance of hierarchical order...)
Heaven's Mirror; Magicians of the Gods - Graham Hancock
The Chronicles of Thomas Covenant the Unbeliever; The Second Chronicles of Thomas Covenant - Stephen Donaldson
Hobbit; LoTR; Silmarillion; Lost Tales - JRR Tolkein
Don Quixote - Miguel de Cervantes
Any book of poetry which includes "The Prisoner of Chillon" - Lord Byron, whether it's a collection of solely Byron or a medley of Byron, John Keats, Percy Bysshe Shelly
Freakonomics; Freakonomics 2 - Steven Levitt & Stephen Dubner
Illiad - Homer
Battlefield Earth - L Ron Hubbard
Pillars of the Earth - Ken Follett
Moonfleet - John Meade Faulkner
That's a top 10 (kinda), so I'll leave it there.
Yours Aye
Mark H