X3: Last Stand directed by Brett Ratner & written by Simon Kinberg,was the highest grossing film of 2006 and the most successful of the series, however the movie was horrible at best.
In 2011, Matthew Vaughn directed X-Men: First Class. The story was set in 1962 and focuses on the relationship between Professor Xavier (Prof. X) & Erik Lensherr (Magneto) and the origin of the X-Men. Some parts of the story were changed and altered and to some extent it hurt the movie as a whole, but from a story standpoint, it was a good looking prequel. 2 major issues were Scott Summers (Cyclops) & Jean Grey being replaced by Alex Summers (Havoc) & Mystique. There was also no Iceman or Angel in this film and that is due to the inconsistencies of X-Men through X3.
When X-Men: First Class director Matthew Vaughan stepped down from doing the sequel, the frontrunner Bryan Singer was there. Bryan explained that a lot of the film will rotate around the comic book arc, however, due to all of the changes that FOX has made to the X-Men franchise film-to-film, it will be a challenge to perfect the craft, we can bandage and correct it...
Already signed on to the film is Michael Fassbender (Magneto), James McAvoy (Prof. X) and Jennifer Lawrence (Mystique). Reprising the roles of their older selves are Patrick Stewart (Prof. X) and Ian McKellan (Magneto).
by: Chris Clairemont and John Byrne
The Uncanny X-Men #141-142
The near future, New York City, had become a nightmarish environment run by mutant-discriminatory robots, known as Sentinels. In present day the X-Men fights Mystique's Brotherhood of Evil Mutants. In the near future however, the X-Men failed to stop the assassination of Senator Kelly. Mutants live on internment camps and the Sentinels run the US.
The present day X-Men are forewarned of a possible hellish future by a future version of their teammate Kitty Pryde, whose mind traveled back in time and possessed her younger self. Even though the assassination was averted, the future was almost exactly the same in a alternate timeline.
The very popular X-Men cartoon in 1993 had a "Days of Future Past" adaptation. Even though it was not exact, it was a very good story. The mutant Bishop travels from 2055 to the present to stop the X-Men from assassinating someone. He turns to the X-Men for help. At the ending of episode 1 Bishop remembers that Gambit is the so-called assassin. The X-Men stop Bishop from killing Gambit and they all go the Washington DC, where the Brotherhood are planning the true assassination of Kelly. Mystique poses as Gambit and tries to kill Kelly, but the real Gambit saves the Senator. Afterward, Bishop goes back home to his time & the future is still the same...
Take a look at the episodes below.