I asked a similar question right after I finished The Expanse and the response I received was to read Revelation Space. Needless to say I wasn't disappointed!
I'm working on The Culture series by Ian Banks now.
That's pretty interesting, I'll have to check his stuff out. It reminds me of my favorite sci-fi book regarding large time scales was The Forever War, which discusses how traveling at the speed of light creates time bubbles for the passengers aboard the ship, essentially the whole general relativity concept. This makes it so that by the time their soldiers get back to their main station hubs from missions, sometimes multiple years/decades/longer have passed. I highly recommend that book to anyone that's never read it and likes sci-fi!