The X-Men is a well known comic book series that many fanboys, like myself, enjoyed for many years. When it gain a cartoon series back in 1992, the team's popularity starts to increase greatly among the general public(unless of course you count that one arcade game with the bad Engrish). And when the X-Men film came out in 1998, every fan out there agreed that the movie will present the X-Men series to the general audience everywhere. The movie was a major sucess and everybody now know who the X-Men are, creating a new found interest in comic books.
However as the films progresses, the series begins to fade due plot lines that have failed to captivate people who enjoy them; mostly due to not staying true to continuity to both the comics and its own universe. To me (and basically majority of the people on this site), I think that if Fox were to try and use other X-Men villains (beside Magneto and Stryker) and their story in thier past films, the fans of the comic and newcomers to the series would enjoy the level of plot diversity in the movie series. Here are those villains and plot that could have been used before.
Sentinels
This one has something all X-Men fans (whether they are true or not) would have liked to see in one of the movies. I mean, come on, world is filled with mutants with dangeerous powers and the humans needed something to protect their asses: the Sentinels. I can't imagine a great X-Men story without the Sentinals hunting all the mutants, capturing to protect everybody, and then enslave everybody on Earth due to some sort of messed up programming. It would have been cool to see these guys flying around and fighting the X-Men; instead all we got was a cheap cameo as nothing but a program in the Danger Room.
In movie plot wise, the Sentinels could have been used in either the second or third film. The second, though it was a good adaption of the "God Love, Men Kills" story, would be good since it deals with humans retaliating towards the recent mutant attacks. And the third would have been perfect since that, obviously, works better than that stupid 'cure' plot line that we all unfortunately have to witness.
Mr. Sinister
The guy is practically a mad, genetics scientist, who does questionable experiments on mutants; WHAT IS THERE NOT TO LIKE ABOUT THIS GUY!?! He kidnaps mutants, then he studies them, then he steals their genetic codes to create armies of super beings to his disposal, then ?????, and then he becomes world leader. This guy is the X-Men equivalent to Wesker of the Resident Evil series.
In movie plot wise, he could have been used in, well, ANY of the films. The second was perfect for his introduction due to that movie's atmosphere and all those mutant kids captured, the third would have made more sence than the 'cure' thing and that Wolverine movie just practically speaks for Mr. Sinister to appear (only with the wrong protagonist in it).
The movies could have just introduced him (as well as many X-Men characters like Havok, Banshee, or even Psylocke) as some mad scientist wanting to rule the world throught the recent apperances of mutants; by manipulating the genetics to give him and his followers powers. But since it is Fox; no original X-Men plot, just a bastard version of Deadpool.
Hellfire Club
Okay, I know, Fox are currently using the Hellfire Club in their recent movie; but honestly, they should have been used sooner anyway. A secret group formed for the sole purpose of gaining power and world domination, add that with all the mutants running around and you got yourself a movie.
In movie plot wise, these guys should have been included in X-Men Last Stand in place of Magneto. The group's inclusion could have gave depth to the whole Dark Phoenix story. They could have been just kidnapped Jean and try to manipulate her to work for them; just like in the comics. This would have made X-Men Last Stand from bad comic book movie to, perhaps, one of the best well adapted piece. Soooo, yeah; Hellfire Club is better used for the 3rd X-Men film than the 5th.
Mojo
This guy . . . . okay I honestly just included him at a pathetic attempt at making comedy on here. Sorry for wasting your time for mentioning this one villain.
All I can say is, that he would have been perfect if they made X-Men into a comedy satire that makes fun of the current super hero trend.
Juggernaut
Okay, he was use in X-Men Last Stand; so I guess I shouldn't complain.
. . . Besides the fact that Fox didn't explore his relationship with Xavier, and made him a mutant instead of a human with super powers, and really went cheap with his costume, and didn't made him bigger than 6'8" (I feel that the Juggernaut in X3 was short).
Shi'ar Empire
. . . I am kind of mixed on whether or not these guys should appear in the X-Men movies. The pro is that this could help explain the existence of the Phoenix inside of Jean during the third X-Men movie. On the other hand, the general audience wouldn't really understand how alien gods tie in with mutant racism.
But hey, it is a comic book movie; since when was anything ever supposed to be realistic (and don't say Batman, his whole character is nothing but fiction when you apply the things he do to real life itself).
Apocalypse
Need I really explain how good this guy could have been used in X-Men films now (not in the past). In retrospect, I think everybody can agreed that Apocalypse should have been one of the elements for the new X-Men film. Fox should have known that their films were failing, so why not include this guy just to save them.
Now as for plot, he should be included as the main villain to this new X-Men film series. Maybe have time travellers like Cable, Bishop, or even Kitty to go back in time to help Professor X create an alternative timeline where the Apocalypse future didn't happen at all. And . . . okay, this is getting a bit reptitive. I am just stating every single fact that would make First Class a better movie; I mean, who knows, mayber the Apocalypse element will tie into this new X-Men movie. Still, it is kind of hard for me to trust Fox after the last two films.
Well thats my editorial (first one, to be precise) on what should have been done for the X-Men movies. I hope this gives any of you guys on some insights on basically how Fox could of made the plots of their X-Men movies better (even though I feel this editorial isn't good enough like all the others).