For me it was The House of Leaves by Mark Z. Danielewski. I really found the weird concept of the book hugely intriguing before when I first heard about the book, and even loved the psychological horror aspects of the story, but by the time I got half way through, I felt almost nauseated from the very same oddities of the writing that I just couldn’t carry on. Maybe one day I’ll pick it up again but I doubt it’d be any time soon.