@Rinel I was the same. I watched the show first on Syfy, so Seasons 1 and 2, then (since it was cancelled) I picked up the books cause I loved the show so much that I just had to know what happened with everything. The story was too good to just stop there. And I loved the books even more. Then Amazon picked the show back up and now I'm in the middle of watch Season 3. Still great.
For those that have read the books, but not seen Season 3, Amazon really lets Chrisjen be who she is in the books in a way that SyFy did not (or could not). It is fantastic.
I love it when you can enjoy the books and the TV show (or movie) at the same time. It doesn't always happen, but even with different story choices for media reasons, the stories just really flow together. Although it is super weird that the TV show series seems to begin and end in the middle of each book, it doesn't feel off at all.
I also love that they've included most, if not all of the Expanse novellas. You can tell the people working on the show have a love of the material.
As far as Science Fiction on TV goes, The Expanse has been one of the best things I've enjoyed in a really long time. Sadly, that was specifically what SyFy was going for when it dumped the budget into it that it did, but it also got cancelled because of that budget.