Both books are a treasure trove of information and history. They are both well written and even for non religious folk can serve as guidance on how to best organize their daily life or at the very least you would want to read them to be more knowledgeable about what the majority of people around you believes in.
This a very personal opinion based on some popular classic book lists like those found on 4chan /lit/ etc.
(Note: All books are new and I calculated the price from Book Depository [0], you might be able to purchase more from Better World Books [1]):
- The Holy Bible
- Moby Dick by Melville
- The Brothers Karamazov by Dostoevsky
- The Master And Margarita by Bulgakov
- Don Quixote by Miguel de Cervantes
- The Iliad by Homer
- The Odyssey by Homer
- Meditations by Marcus Aurelius
- The Count of Monte Cristo by Alexandra Dumas
- The Decline of the West by Oswald Spengler
- The Qur'an
- The Prince by Machiavelli
- The Art of War by Sun Tzu
- Crime and Punishment by Dostoevsky
- The Confessions by Saint Augustine
- Les Miserables by Victor Hugo
- We by Yevgeny Zamyatin
- The Book Of Five Rings by Miyamoto Musashi
- The Bridge on the Drina by Ivo Andric
- Bosnian Chronicle by Ivo Andric
- Growth of the Soil by Knut Hamsun
- Storm of Steel by Ernst Junger
- All Quiet on the Western Front by Remarque
- The Divine Comedy by Dante