Most sci-fi game settings don’t work for me for one reason or another, and I tend to read sci-fi books that don’t really involve war for the most part, more into exploration and adventure. Most of what I would or do game in sci-fi is more from TV and movies. I like Star Trek (TOS style) for ship combat, would love to skirmish in a Firefly setting, and probably would enjoy gaming in an adaptation of 5th Element universe as well.
My sci-fi gaming tends to take the form of near-future and post-apoc. Again, movies and TV provide much of the near-future stuff with a mix ranging from Bladerunner to Mars Attacks. Post-Apoc comes much more from books than TV/movie inspiration, but again is a compilation of bits ranging from A Canticle for Leibowitz to The Texas Israeli War (in the same game).