Sigh I really don't have time for more gaming but I guess I need to make an exception for this one...
The books and TV series are fantastic and I want more on the same.
I went on a long search for anything that had some similarity to the series. To be honest, it's hard since "The Expanse" series is an interesting combination of a few different things that make it unique.
But, I did eventually find a few other series that had their own unique qualities that managed to leave me with a similar feeling when completed. Most recently, the Dead Empire's Fall Trilogy from Walter Jon Williams (and the second trilogy in the same universe). But, I was also really impressed with John Scalzi's Interdependency Trilogy as well. And lastly, the Murderbot Diaries from Marth Wells was a whole bucket of interesting twist on a scifi world that left a truly unique impression on me. Though, the last example is still not complete with a new book coming out this year or next year I think.