What I like about good hard sci-fi is that it even challenges the very laws of physics as the absolute limits to what's imaginable, in dire contrast to a daily reality of the lowest of lowly aspirations grinding to a halt amid a suffocating runaway expansion of made-up constraints created by regressive forces and maintained by subservient drones with no imagination or humour
@pkw let me see... off the top of my head: Schild's Ladder, Dragon's Egg, The Three-Body Problem, and not quite in the hard sci-fi category but also: The Hitchhiker's Guide to the Galaxy, The Star Diaries, The Man in the High Castle, Borges's Labyrinths, and the novels of Vonnegut and Murakami.
With the caveat that I read some of these many years ago and my memory of them might be rosier than how I might find them if I were to read them now.
@pdt Thanks! I liked the Three-Body Problem.
I know what you mean about tastes changing, got it :)
@pdt Have any recommendations ?