As a big fan of the TV show, I was a bit underwhelmed by the first book, Leviathan Wakes, but they certainly have picked up speed since. Caliban's War was really good, and Abaddon's Gate is better. I like how the authors can keep widening the scope of the grand narrative so that every time you think you've gotten the plot pinned down, they "zoom out" and reveal that it was just a part of the greater picture.

If the writers keep up this stride, it'll be very interesting to read a few books from now.