If I never read the comics, I would love this movie. It was a pretty big let down though when it comes to the true story and how much they changed. As it has been said already, it did not stick to the comic book. The Phoenix saga just shouldn't of been the script they used. Anyways, here are few things I caught wrong within the movie:

- Wolverine's regeneration ability is not as quick as they interpreted it to be in the movie.
- Colossus is suppose to be Russian
- Storm is suppose to be from Africa
- They completely rewrote how Jean becomes possessed by the Phoenix Force. From Marvel.com "After Jean and the X-Men defeated scientist Stephen Lang and his robotic Sentinels on his space station, the heroes escaped back to Earth in a shuttle through a lethal solar radiation storm. Dying from radiation poisoning, Jean was saved by the cosmic entity known as the Phoenix Force who created a duplicate body complete with memories and personality, absorbed a portion of her consciousness and cast her into suspended animation in a strange cocoon at the bottom of Jamaica Bay.

For months the Phoenix believed itself to be the real Jean until mental manipulation by Mastermind caused it to go insane and become Dark Phoenix. Ultimately, the portion of Jean's consciousness within Phoenix resurfaced, causing it to commit suicide. Eventually, Jean was rescued from her stasis and, with the other original X-Men, formed a new team, X-Factor."
Also she's supposed to be fiery.

- Still don't understand why they didn't have one of the coolest characters in there: Gambit. Gambit obviously is the one in love with Rogue; not Ice Man.

- Angel is supposed to be older than what he was in the movie. Same with Ice Man and Pyro. At least they didn't make Angel's wings metal because that doesn't occur till he almost dies and Apocalypse reconstructs his body.

- Rogue is supposed to be able to fly.

- Juggernaut is Professor Xavier's half brother and his helmet is supposed to give him his power. That was never even uttered.

- Magneto should have done more destruction even though the Mystique rescue scene was top notch bad ass.

- If they don't have a 4th X-Men movie (I hear there won't be a 4th regardless of what the movie's ending is) then they ruined so much by taking away Cyclops since he and Jean have children.

Perhaps they were just trying to make a movie that people didn't know the plot and didn't know what was going to happen. I believe they should have made an entirely different movie with entirely different characters with a completely different movie title and just used the manipulated X-Men scripts for it. They should have left it up to someone else to make the movie true to the comic book. Sure, take a few things out such as the spandex looking uniforms they originally wore. I was fine with that. As I said, the movie was good in it's self and I did enjoy it. There was lots of things I was looking forward to seeing but it's too bad they didn't happen. I'll be the guy who directs a Dead Pool movie though!