I love sci-fi and I don't know how I missed this the first time around, but I just finished binging The Expanse through Season 3 and this is the best TV sci-fi since Babylon 5. I love this show! A few scattered thoughts/vague spoilers (be warned) follow:
1) I love world building, the three societies (Earth, Mars, Belters) are really cool, similar with shared humanity but different due to the worlds they live on (I love the Belter patois) (Side note, I loved when Naomi in Season 3 slipped into her Belter dialect when she was working with the Belters)
2) The zero G of space is really cool and I love how they remind you of that all the time - the constant klink klink of walking, dead people floating or belted in seats with arms up, stuff floating. The most amazing scene which I don't know if anyone caught was in season 3 when a woman we impaled hanging from the ceiling. As she was dying she was crying but rather than the tears sliding down her face they pooled in her eyes. It was amazing they thought of that.
3) The battles in space (especially the R vs. a certain ship) are fantastic and seem so grounded in a lower tech reality. No shields, no unlimited manuevering, holes get punched in ships, vacuum is a constant danger.
4) I love the crew, every single one of them. They are real people with flaws, they make mistakes (some quite bad) and they grow/change as people.
5) Shohreh Aghdashloo as Chrisjen Avasarala steals every scene she is in. She has just the thinnest veneer of sugar coating her piss and vinegar. She also gets the best outfits - even when she got on a spaceship, her space outfit was the most stylish of the series

6) I also found interesting the "reboot" of the show in the third season. The show started out as a political/military/mystery thriller and then it became a 2001/space exploration show. The change started off slowly but wow, did that end in a big reveal!
7) I love Amos but I think he is a psychopath who just happened to find the right people to direct him. I also love Drummer, she takes no prisoners
That's all for now, gotta start Season 4 now. Just had to say something about my new binge crush. I love this show!