Spider-Man was never a member of the Fantastic Four. He was a member of the New Fantastic Four and Future Foundation. Aside from that...She-Hulk or Wyatt Wingfoot has to be my favorite non original member.
Some actors just don't get it: You may be bigger than some movies, but you definitely aren't bigger than this FRANCHISE! If anything you take LESS money for this movie so you can charge MUCH MORE for other movies.