Important persons

Behind the Avengers there are alot of people - some do we know - others not. Without them "The Avengers" wouldn't be as successful as they are now. So who, do you think, is the most important person/ are the most important persons behind the show?
The actors, script writers, stunt arrangers, ... there are so many and most of the time we're just talking about the actors - because we've seen them.

But I think we should also collect all the names of the people behind the cameras, co-actors and so on, so let's start a list.