What's Your Favorite Sub-Genre Of Science Fiction?

[Altair]

Science fiction is a broad and diverse genre, encompassing everything from time travel to space opera to cyberpunk.
What is your favorite science fiction subgenre, and why?
---
Personally, I'm a big fan of hard science fiction. I love stories that explore scientific concepts and speculate about what could be possible in the future. I enjoy the way these stories challenge my mind and expand my understanding of the world around me.