How about an X-Men prequel? It gives more of a chance to some characters who haven't or don't show up in the current series also those who don't get as much screen time. I'd like to see a prequel have Jean, Storm, Cyclops, Beast, Gambit, Bishop, Colosus. I know it's not the same whithout Wolverine but having his own spin-off makes sense not to include him. Give it kinda old school feeling, first real battle between the Brotherhood and the X-Men.