I enjoy this sort of thing very much. My brother and I used to make up lists of Top Ten Conductors, Top Ten Violinists , etc. and argue about them. It’s silly, as you say, but fun. I agree that 13 Good Ghost Stories is a better title than 13 [Any Superlative], because the limiting number is bound to exclude lots of first-rate things. How about a new title: 13 Little-known , First-rate Ghost Stories? My list would include:
The Cyclops Juju, Shamus Frazer (or the one about Guy Fawkes Day)
The Library Window, Mrs Oliphant
Pargiton and Harby, Desmond MacCarthy
The Travelling Grave, L. P. Hartley
The Green Bottle, Bernard Capes (the best of all, I think)
A Haunted House, Algernon Blackwood
Mr Justice Harbottle, Sheridan LeFanu
PS I’m glad to see Pollock and the Porroh Man and Thurnley Abbey on your list. For Burrage, I prefer A Night in the Wax Museum, though it’s not a ghost story.
I have to add Stevenson's The Body Snatcher, though it only turns supernatural at the very end.