I watched season one after reading the first book, Leviathan Wakes, which I really enjoyed. The TV series is no way as good as the books, and I think the TV show doesn’t do the best job of making sense of what isn’t a terribly complex story. I’m much more at home with the books now.
Season 2 was ok. Not amazing again, but certainly in keeping with the first season. Apparently season 3 is already being filmed, which is a good thing I believe. I’ll certainly watch it.