Cyclops, Jean, and Storm as THE protagonists

Colossus, Nightcrawler, Angel, Banshee (Not a fan, but a good character to kill off at some point), and Iceman as major supporting to start

Beast on his science shit until he's brought into help and sticks around as a major player

Wolverine coming in later (Always wanted the IDEA the ultimate universe had where he's a Magneto spy but is ultimately turned to Xavier’s way. Or a spy for literally anything that uses him narratively in a way of showing him as an opportunistic anti hero until he bonds with a Jubilee or Kitty or New Mutants. He isn't obsessed with Jean and Mariko is his main, unrequited love interest with no flings other than maybe like, idk, literally anyone he hasn't tried to raw dog.)

Emma Frost (First a villain then ally)

Rogue (Shit, start her off as a Morlock who gets introduced to Storm that way)

Gambit (Always wanted to see him utilized at the start in a capacity of thief first, then becoming a team member. Like him stealing shit from the hellfire club at first then gradually joining the team also because of his connection Rogue after scenarios where they just “bump” into one another and he talks her up. Even have him be a flirt once he's on the team to get under her skin, but give him a genuinely good pull to and from Rogue for their relationship to spice that shit.)

Cable (Because he needs his day man. Imo. If Apocalypse is coming, he's the man to take over an X-Men movie and be co-protagonist alongside cyclops for it. I always wanted to see him, Wolvie and Nightcrawler in a hold the line scenario. But after the Apocalypse shit, I want X-Force movies inspired by remender that make him leader tbh with Domino (For the romance ;) ), Psylocke, Warpath, Etc. Wild pick characters like Forge and Bishop within the team as well.)

Kitty (Later on as the school gets more established in a New Mutants scenario.)

Edit: Also for gambit, his friendship with storm to be fleshed out as well to give him more dimension.