Fight Club. It wasn’t fun to read it felt like the author was ploying with me trying purposefully to confuse me to a point where it forced me to become disinterested. However with the movie i was captivated every second. The book’s attempt to obscure and mystify the reader might have been an intentional stylistic choice, but for me, it didn’t translate well.
Didn’t see anyone else mention it so I’ll say Rosemary’s Baby. The novel is almost too slow a burn, and just ends up being sort of a boring slice of life novel sprinkled with the occasional “Oooh, ominous!” moment, whereas the movie condensed those moments into a more pervasive atmosphere of dread.