Honestly, can you hate a book? I am not sure. I think, you can dislike a book and the easiest way to deal with it is to stop reading it. That’s what I usually do. Therefore, I can’t be really objective when choosing the book I hate most.
However, I can say that I do not really like any kind of science fiction novels (e.g. „On the beach“ by Nevill Shute) and I did not like reading „Travells with Charley“ by John Steinbeck. I am also not a great fan of writings by Theodor Fontane, to name a German author, although I know that some of his writings are supposed to be great literature. Maybe that’s a question of age and I can approve that when I am older?