This challenge combines the results of two lists. The first 237 books are those which scored over 16% on the mega-challenge "1000 Books You May Have Actually Read'" and so must have been read by at least 50,000 users of this site.
The remaining books are those which also scored over 16%, but in this case on my related challenge "Goodreads Highest Rating Books (200,000 to 1,000,000+)". I did not repeat books already in the first 237. Because Readerof1000's challenge only includes the 1st book in a series, my contribution comprises the remaining books of those series. It also features single books which cracked 16%, but only in my challenge, probably because of the more voracious reading behaviour of the regular List Challenges users.
Thanks to Readerof1000. Follow the link to Readerof1000's original list (as if it needs any further promotion, he says with jealousy). Both parts of the list in descending order of popularity.