When it comes to realistic sci-fi series, The Expanse books by James S. A. Corey are often held up as the gold standard. So far as book series that have been adapted for the screen, The Expanse is definitely among the most realistic, but in terms of book series in general, it has a lot of competition. Mars trilogy by Kim Stanley RobinsonThe Multi-Colored PlanetCredit: Spectra The Mars trilogy consists of three books: Red Mars (1992), Green Mars (1993), and Blue Mars (1996). There's plenty of intrigue and human drama in the Mars trilogy, as various factions fight each other over how to live on the Red Planet. The Revelation Space series is a proper space opera, with lots of interstellar conflicts and post-human entities and threats to all life in the universe.