This is just download stats from archive.org. Multi-volume audiobooks’ stats have been added together. Obviously, multi-part audiobooks are going to use up more downloads, and I haven’t adjusted for that because I’m lazy.
1. 51, 532 downloads: Against Heresies by St. Irenaeus of Lyons.
2. 27, 710: Fifty-One Tales by Lord Dunsany.
3. 21,591: Fatherless Fanny by Anon.
4. 19,529: The Eye of Osiris by R. Austin Freeman.
5. 19,265: The Dialogues of St. Catherine of Siena.
6. 17,657: Mr. Sponge’s Sporting Tour by R.S. Surtees.
7. 17,355: The Ascent of Mount Carmel by St. John of the Cross.
8. 15,588: Pastoral Care by St. Gregory the Great.
9. 12,882: Little Fuzzy by H. Beam Piper.
10. 12,749: The Everlasting Man by G.K. Chesterton. (Which might be in the public domain in the US and might not be. Bah.)
11. 12,610: Gerusalemme Liberata by Torquato Tasso.
12. 10,569: The Imitation of Christ by Thomas a Kempis.
13. 9,797: The Red Thumb-Mark by R. Austin Freeman.
14. 9,093: The Dark Night of the Soul by St John of the Cross.
15. 8,393: “The Wondersmith” by Fitz-James O’Brien.
16. 8,038: The Worm Ouroboros by E.R. Eddison.
17. 7,430: The Civil War (aka Pharsalia) by Lucan.
18. 7,144: “Speech on Reconciliation with America” by Edmund Burke
19. 6,323: The Lani People by J.F. Bone.
20. 5,824: Dawn of Flame by Stanley G. Weinbaum.