Continuity and yet new and exciting plots? Recurring characters? An overall plot? Do you read specific series for the world an author has created or the ever changing plots? The big end game? The good vs evil?
Continuity. By this I'm talking about the world. It's the little things that matter, right? But what if a hint of those little things had been introduced in previous stories? Would that be acceptable? Little clues to mysteries and such.
But what about the characters? Do you like to see characters from previous books make cameo appearances? Or do you prefer more substantial roles? Or do you even prefer a series of books following a couple?
Now personally, I like a good over-arcing plot. I like to ferret out details, the mystery, the whodunit of a longer story. My problem is when an author elongates the mystery for the sake of sales. Now, as an author myself, sales are important. But as a reader, don't cheat me.
What are your favorite series? What do you like to see included in one?