The first Jonathan Carroll book I ever read. Fantastic. Literally.
In Praise of Idleness by Bertrand Russell.
You kinda should read all of Iain Banks' Culture novels in order but Excession is phenomenal.
Devices and Desires by K. J. Parker. An incredibly well-written 'fantasy' book for intelligent adults.
Easily Kafka's best.
I have read this more times than is strictly healthy.
My favourite book ever. Originally bought because I liked this cover. Judge.