For serious book, Soldier of the Great War is my favorite piece of fiction. THUD! is just a whole lot of fun (Fantasy) by Terry Pratchett is brilliant! No SiFi on he list, but Dune and the Foundation trilogy are fantastic. Ender’s Game is amazing.
Path Between the Seas and John Adams both by the same author are about as good non-fiction books you can get.
More great books! Thank you for sharing that! Will check them out for sure.