Most Wished for at Book Depository
This challenge comprises the "Most wished for books" at bookdepository.com as of 15th April 2019. It seems to cover almost all genres, with lashings of self-improvement books. I am not sure if the books are in descending order of "wishingness" on the web site but I have maintained that order anyway, while eliminating duplicates. Some reference works & children's picture books have been omitted.
avg. score: 19 of 230 (8%)
required scores: 1, 10, 15, 20, 28