9. Fatal Attractions
From a distance, Fatal Attractions seems like a standard, cookie-cutter X-Men storyline. Magneto leads a band of mutants with the final goal of wiping out humanity.
However, it is the severity of the consequences suffered by heroes and villains alike that make Fatal Attractions a must-see for fans of the MCU. The infamous image of Magneto pulling the Adamantium from Wolverine's bones and through his open wounds is one that has gone down in X-Men's history, and could create something of a depression angle for Wolverine, now weakened and using bone claws.
Fatal Attractions could also introduce the Shi'ar in to the MCU, although they will be introduced in Fox's X-Men Dark Phoenix, and we could see Professor X don a Shi'ar exoskeleton to join his X-Men in battle, something we have never even come close to seeing on screen before.
Fatal Attractions could potentially also write Magneto out of action for a few movies, sustaining his allure for a later title, as Professor X mind wipes his mortal enemy, leaving Magneto in a coma.