Don Quixote for me, too. I barely even got started. I just couldn't find anything to get hold of, so to speak. I do intend to try again one day.
Many years ago, when I was a poor student, I used to buy cheap out-of-copyright classics from discount bookstores, and I used to buy them by weight, essentially, to make sure my money stretched as far as possible. I distinctly remember turning down the slender pamphlet that was
Heart of Darkness.
I read
War and Peace - excellent value -
The Adventures of Sherlock Holmes, The Three Musketeers, etc, and I think
Don Quixote is the only one I still own.
They're all free ebooks nowadays. You kids don't know you're born.
Dune Messiah I have tried a couple of times, and failed to get anywhere with. I loved Dune, but this just seems to overcomplicate it.
I also failed
The Two Towers at my first attempt, but managed it second time round. (I still think Fellowship is the best of the three.)