I usually care more about the ideas than characters / prose and the recs below kinda reflect that.

Anyways, in no particular order ...

  - Adiamante by Modesitt (1996), pacifist environmentalists vs cyberpunk warmongers. It's a lot of philosophy and a bit preachy at that but the world building was pretty thorough.
  - Last and First Idol by Gengen Kusano (2018). Similar to Last and First Men by Olaf Stapledon, it parodies various aspects of Japanese culture over a period of eons. (It's a set of three ~70pg stories).
  - Harry Potter and the Methods of Rationality by Eliezer Yudkowsky (2010). Parody where the main character investigates how to exploit magic. Kind of like xkcd / what-if but in the Harry Potter universe. Author is controversial and the story's pompous /r/iamverysmart vibes can be offputting but I enjoyed it.

Also want to second some of the other recs in this thread.

  - Greg Egan's stuff
  - There is No Antimimetics Division by qntm
  - Sequels to Enders Game and the Ender's Shadow spinoffs by Orson Scott Card.
  - Dragon's Egg and its sequel by Robert L. Forward.