As I see others have included the most important economics works already (Wealth of Nations, Road to Serfdom, The Law, Economics in One Lesson) and Tolkien/C.S. Lewis, I'll have to toss out some lesser works:
The Count of Monte Cristo (not a lesser, work, though)
The Aenid
Beowolf
The Once and Future King
The Brothers Karamozov
The Sea Wolf (or White Fang or Call of the Wild. I'd prefer all three.)
Huckleberry Finn
The Silmarillion (you have to be a significant Tolkien fan and mythology buff to enjoy the beginning of this one, though.)
Dr. Faustus
The Gallic War (de Bello Gallico)
Livy's History of Rome
The short stories of Edgar Allen Poe (my preference is for his detective stories, I believe the first of their kind). Be careful with Poe, though. He well understood the darkness of the human soul, generally focusing on madness and evil. (Though not solely; his detective stories are some of the exceptions.)
Meditations by Marcus Aurelius
Frankenstein
The Tempest
(I had better stop because I'm pretty sure I'll keep coming up with works if I continue to think on this.)