The Silmarillion --- by J.R.R. Tolkien
I liked that one, though Lord of the Rings is definitely better.
Wasn't that actually a collection of Tolkein's notes and ideas for The Hobbit and The Lord of the Rings? I read about fifty pages of it and I gave up. I needed more note paper than the book had pages to keep up with the myths, gods, and everything else that was going on.
I tried that at age 12. It came in a five book set with 'The Hobbit' and the LOTR trilogy (I know, I know, it's one book and not a trilogy) and I started with 'The Silmarillion' first. It was years later before I actually read the other books which were where I should have started first, ignoring 'The Silmarillion'.
"Mein Kampf"
God sakes, the things that two men will do when they're locked up in prison together. I was almost willing to release Rudolf Hess from prison after reading that book based on the idea that he suffered enough having to sit next to Hitler in jail all those years transcribing that idiocy while Hitler dictated to him. No wonder Hess went crazy. I can't believe that any Nazis actually read that book.