Looking for interesting fiction (preferably sci-fi, or fantasy, but will accept horror suggestions) that manages to strike a good balance between taking itself seriously/having interesting ideas and leaving room for hope and humor.

I love sci-fi and fantasy, but over the years I've become increasingly picky. I want books that have interesting ideas and give the reader things to chew on, while not being so heavy as to be grimdark, dense, or navel-gazing. I want books that have moments of humor and light, without feeling stakeless or sarcastic. [...]