X-Men: Apocalypse
Might as well start this.
So apart from just being about Apocalypse it seems this film will show us the real first class. Consisting of a young Cyclops, Jean Grey and probably Storm too:
https://uk.movies.yahoo.com/classic-x-men-return-x-men-apocalypse-091500928.html
I'm guessing Beast will still be in it, so it will be close to the actual First Class from the comics. Just missing Angel and Iceman.
Will Cyclops finally get the cred that he deserves on the big screen? Doesn't help that he will be a teenager though. There will also be continuity problems with the Cyclops meeting Xavier scene in Origins: Wolverine, and the Xavier meeting Jean Grey scene in X3.
Not sure how they are going to age Charles, Eric and Beast either. Because this movie will have to skip another decade.