I’ll go with the low-hanging fruit: Mein Kampf. I’ve read it, cover to cover. As a piece of propaganda, it’s good. As an example of good writing? Absolutely not (though I will admit I have only read it in translation). Oh, and the whole fascist, racist, and generally shitty worldview of the author that he infuses into the text. And the fact that the author is literally Hitler. You 5-star that book? You’re a Nazi. Period. And as a Jewish person, I don’t look too kindly on them.
I remember a conversation with one guy who was raving about how exciting the book was, saying something like “didn’t you find all those coincidences amazing?”, which suggested to me he thought it was real. I don know what he thought of the guy learning to levitate at the end though.