Trivial trivia: On reflection, I suspect that Charlie may edge out even Tessa for a fourth place by "count of credits" alone, because -- I think? it's been a long time! -- he was in the opening credits of many more episodes than he appeared in: all of second season, or at least episode 2 on, and the first 13 episodes of third season (up to the go-to-Paris switch at the halfway point). (Anne is definitely out of contention; quite right!)