Flatland: https://www.gutenberg.org/ebooks/search/?query=flatland

I've heard good things. Also - Sherlock Holmes :)

Not a recommendation per se but I used to use Amphetype on Gutenberg texts to practise touch-typing. There's something about writing out a book that hits differently to reading it. You skip less, odd parts stick with you. I think the last one I tried was The Island of Dr Moreau.

From the newest releases page I stumbled into "Some Nigerian fertility cults" by Percy Amaury Talbot & am enjoying it so far.

https://www.gutenberg.org/ebooks/78684