"This is a list of books that leave you in a daze engrossed in thought while and/or after you finish reading them." (Goodreads). The works are from a multitude of genres, both fiction and non-fiction (and, unsurprisingly, include the Harry Potter series yet again).
As is often the case with lists ranked in descending order by votes, the choices become increasingly interesting the further one sinks into the challenge. To be included: 1000+ ratings on Goodreads & at least two votes.