Hi,
This is a totally new universe, slightly (if not heavily) diverged from its Marvel 616 counterpart, so let's clear the things up for the sake of the moviegoer fans.
Criterion of evaluation:
Addition of a member - it actually reinforces the current line-up/mark, but doesn't change it.
Leaving of a member - the departure implies a 'transitory mode' for the current line-up/mark.
Replacement of a member - it gives life to a new line-up/mark.
X-MEN - MARK I (pre-2000)
Cyclops
Storm
Beast
Note: Jean Grey was busy as genetist, and I doubt she worked as an X-Man at that point (she also didn't get a proper codename). Probably, Professor X kept her in the shadows just to prevent her psychic powers to grow up and "awake" Phoenix's personality.
The beginning, where Cyclops and Storm rescued Wolverine and Rogue from Sabretooth's claws, seems to reinforce the theory.
Beast left the roster to "perform" as ambassador of the mutant rights.
So, basically, the team became what you see in the beginning of 'X-MEN' - Two elements and Jean Grey still "in the making" as supporting member.
X-MEN - MARK II (2000)
Cyclops
Jean Grey
Storm
Wolverine
Note: the first movie, 'X-MEN'. Rogue was an X-Man long time before she would realize that. Anyway, she's even an "instrumental" device in Magneto's hands.
Jean Grey joined the team as "effective" member along to Wolverine, and the scene where she telecinetically moves the discs towards Cyclops could be the very first time she's actually wearing the uniform.
X-MEN - MARK III (2003)
Cyclops
Jean Grey
Storm
Wolverine
Rogue
Iceman
Nightcrawler
Note: the second movie, 'X2: X-MEN UNITED'. Jean Grey "died" at Alkali Lake to lately resurrect as 'Phoenix'. Colossus wasn't even part of the team, maybe a guest. Rogue was still learning how to use her powers, but she was an X-Man. The beginning of 'X-MEN 3: THE LAST STAND' - showing Rogue in the Danger Room along with her mates - officially confirms the theory. She was also a pivotal element in either the defeating of Magneto on Liberty Island and the Alkali Lake events (she piloted the Blackbird).
Nightcrawler presumibly left in the 2003-2006 arc for unknown reasons.
X-MEN - MARK IV (2006)
Storm
Wolverine
Colossus
Iceman
Shadowcat
Rogue
Beast
Angel
Note: the third movie. Rogue left the team to enjoy her new-found "human-like" life.
On a side-note which tastes like spoiler, I have the positive feel that Angel joined the team after the Alcatraz events, even if not explicitly shown or stated (the end of 'X-MEN 3: THE LAST STAND' seems to suggest so). Anyway, I inserted him in the roster as I previously did with Nightcrawler in MARK III, because they all played a major role in the corrispective final battles.
I have to add that Angel had already introduced himself to the school some time before the confrontation, so here we go.
This is a totally new universe, slightly (if not heavily) diverged from its Marvel 616 counterpart, so let's clear the things up for the sake of the moviegoer fans.
Criterion of evaluation:
Addition of a member - it actually reinforces the current line-up/mark, but doesn't change it.
Leaving of a member - the departure implies a 'transitory mode' for the current line-up/mark.
Replacement of a member - it gives life to a new line-up/mark.
X-MEN - MARK I (pre-2000)
Cyclops
Storm
Beast
Note: Jean Grey was busy as genetist, and I doubt she worked as an X-Man at that point (she also didn't get a proper codename). Probably, Professor X kept her in the shadows just to prevent her psychic powers to grow up and "awake" Phoenix's personality.
The beginning, where Cyclops and Storm rescued Wolverine and Rogue from Sabretooth's claws, seems to reinforce the theory.
Beast left the roster to "perform" as ambassador of the mutant rights.
So, basically, the team became what you see in the beginning of 'X-MEN' - Two elements and Jean Grey still "in the making" as supporting member.
X-MEN - MARK II (2000)
Cyclops
Jean Grey
Storm
Wolverine
Note: the first movie, 'X-MEN'. Rogue was an X-Man long time before she would realize that. Anyway, she's even an "instrumental" device in Magneto's hands.
Jean Grey joined the team as "effective" member along to Wolverine, and the scene where she telecinetically moves the discs towards Cyclops could be the very first time she's actually wearing the uniform.
X-MEN - MARK III (2003)
Cyclops
Jean Grey
Storm
Wolverine
Rogue
Iceman
Nightcrawler
Note: the second movie, 'X2: X-MEN UNITED'. Jean Grey "died" at Alkali Lake to lately resurrect as 'Phoenix'. Colossus wasn't even part of the team, maybe a guest. Rogue was still learning how to use her powers, but she was an X-Man. The beginning of 'X-MEN 3: THE LAST STAND' - showing Rogue in the Danger Room along with her mates - officially confirms the theory. She was also a pivotal element in either the defeating of Magneto on Liberty Island and the Alkali Lake events (she piloted the Blackbird).
Nightcrawler presumibly left in the 2003-2006 arc for unknown reasons.
X-MEN - MARK IV (2006)
Storm
Wolverine
Colossus
Iceman
Shadowcat
Rogue
Beast
Angel
Note: the third movie. Rogue left the team to enjoy her new-found "human-like" life.
On a side-note which tastes like spoiler, I have the positive feel that Angel joined the team after the Alcatraz events, even if not explicitly shown or stated (the end of 'X-MEN 3: THE LAST STAND' seems to suggest so). Anyway, I inserted him in the roster as I previously did with Nightcrawler in MARK III, because they all played a major role in the corrispective final battles.
I have to add that Angel had already introduced himself to the school some time before the confrontation, so here we go.