No, not that X-Men #1! The one that Claremont and Lee did!
The Guinness World Records Book presented writer Chris Claremont and Marvel Publishing COO, Jim Sokolowski, with the award for the highest selling single comic book for 1991’s X-MEN #1!
For those of you who own the comic (like yours truly), you’ll know it marks the beginning of some of the most discussed and celebrated runs on the title with Claremont at the helm, and was the beginning of one of the most famous arcs – Mutant Genesis. Featuring Magneto’s triumphant return as well as the dawn of Asteroid M, it was the beginning of some of everyone’s favorite childhood memories in comic books.
Congratulations to Marvel and Claremont on the exciting award!
(source)
