From A Thousand of the Best Novels - Fourth Edition (Newark Free Library, 1919):
It pleases some to write the fanciful romances. They lay the scene in fairyland, in Caesar's Rome, in Cromwell's England, or in a Kansas country town, as is to them easy and attractive. If well done they seem true to fact as one reads them.
They portray men and women who seem like the men and women of our daily experience. Between this good romance and the best of realistic novels, who can draw a line of separation?
The complete list is online thanks to archive.org. I've gone through and picked out a few titles of genre and personal interest, these are all below the jump. I've also included the price and publisher as included in the original publication.
- Barrie, J.M. Peter and Wendy ($1.50. Scribner)
- Bellamy, Edward. Looking Backward: 2000 - 1887 ($1.25. Houghton)
- Chambers, R.W. Cardigan ($1.50. Harper)
- Chambers, R.W. Lorraine ($1.50. Harper)
- Chambers, R.W. The Reckoning ($1.40. Appleton)
- Chambers, R.W. Red Republic ($1.50. Putnam)
- Corelli, Marie. Romance of Two Worlds ($1.00, Burt)
- DeMille, James. Strange Manuscript Found in a Copper Cylinder ($1.25. Harper)
- Grey, Zane. Riders of the Purple Sage ($1.50. Harper)
- Haggard, H.R. Allan Quatermain ($1.25. Longmans)
- Haggard, H.R. Cleopatra ($1.25. Longmans)
- Haggard, H.R. King Solomon's Mines ($1.25. Longmans)
- Haggard, H.R. She ($1.25. Longmans)
- Hornung, E.W. Rogue's March ($1.35. Scribner)
- Hornung, E.W. Witching Hill ($1.35. Scribner)
- Hudson, W.H. Green Mansions ($1.75. Knopf)
- Jokai, Mor. Black Diamonds ($1.60. Harper)
- Morier, James. Adventures of Hajji Baba of Ispahan ($.70. Dutton)
- Poe, E.A. Tales ($1.25. Century)
- Stockton, F.R. Adventures of Captain Horn ($1.50. Scribner)
- Verne, Jules. Around the World in Eighty Days ($1.00. Burt)
- Verne, Jules. From the Earth to the Moon ($1.00. Burt)
- Verne, Jules. Michael Strogoff ($1.00. Burt)
- Verne, Jules. Mysterious Island ($1.00. Burt)
- Verne, Jules. Twenty Thousand Leagues Under the Sea ($1.00. Burt)
- Wells, H.G. New Machiavelli ($1.50. Duffield)
- Wells, H.G. The Time Machine ($1.00. Holt)
- Wells, H.G. War of the Worlds ($1.50. Harper)
- Weyman, Stanley. House of the Wolf ($1.25. Longmans)
- Weyman, Stanley. Long Night ($1.35. Doubleday)
Many other authors of genre significance are also on the list, including Cooper, Dickens, Doyle, Dumas, Ebers, Harte, Kipling, Oppenheim, Orczy, Scott, Sinclair, Stevenson, Twain. Everything, of course, is available through archive.org or Project Gutenberg.
Missing are Algernon Blackwood (early works), Lord Dunsany and Arthur Machen. A few of Lovecraft's short stories had been printed by 1919, but not remotely enough to qualify.