The X-Men
The X-Men return home to find Professor X alive, having faked his death while Changeling masqueraded as him. Xavier reunites with his students and they collectively channel positive energy through him to drive off the alien Z'Nox invasion.
Collects The X-Men #56-65. Neal Adams groundbreaking late-60s X-Men art that redefined superhero visuals.
Collects The X-Men #32-66, X-Men Classics Starring the X-Men #1-3. Silver Age X-Men from the Thomas/Roth era through Neal Adams transformative run.
Collects The X-Men #46-66. Silver Age X-Men - the final stretch featuring Havok, Polaris, and the Sentinels.
Collects X-Men #49-66. The late Silver Age era -- Havok and Polaris debut, new villains emerge, and the original teams final issues before cancellation.
Collects The X-Men #56-65. The legendary Roy Thomas and Neal Adams run that revitalized X-Men with the Sentinels and Savage Land.