We all, I suspect, have read at least one series in its entirety. (Although I can’t imagine having read all 49 of the In Death books. 49!) For the purpose of this discussion, let’s assume that a series is a set of linked books four or more in number. A stellar series has characters whose outcomes you care for and thematic consistency. The best have engrossing world building and offer an immersive experience that deepens with each book.
Romance is rife with series but which ones are spectacular? And do some genres lend themselves more to serieses than others? What do you require in a series? Which one is THE VERY VERY BEST?