Of all the characters Stan Lee co-created with his brilliant collaborators at Marvel Comics in the '60s, a roster of heroes and villains that includes some of the most well known fictional characters in all of pop culture, the greatest creation of all might have been Stan Lee himself. Born Stanley Martin Lieber, "Stan Lee" was the pen name he adopted to put on his comic work, believing he should save his real name to put on the Great American Novel he hoped to write. Of course it was his supposedly lowly work in comics that eventually made Stan not just famous, not just respected, but immortal.
Aside from his scripting that imbued superheroes with the kind of flaws and foibles and layers of personality that comic book heroes had never known before, it was his fabricated persona of Stan "The Man" that really made him a legend. The measure of Stan's contributions to the creation of characters like Spider-Man, the Fantastic Four, The Hulk and so on is contentious to some fans who argue that he stole too much credit from the artists involved, most notably from Jack Kirby and Steve Ditko. What percentage of that is true is impossible to determine. That Stan successfully made himself the public face of Marvel is not.
As much as Stan acknowledged his co-creators over the years and as much as the names of those collaborators continue to appear along side Stan's in the credits of every Marvel movie, the fact is that "Stan Lee" stands alone as the name most associated both with the characters and with Marvel itself. This was not accidental. It was something that Stan manifested into existence through a mix of shrewd calculation and sheer force of will. Some may have resented him for this but I believe that if he hadn't been the personality he was and he hadn't given Marvel its public face, that the work he and his collaborators did would not have achieved the same level of notoriety.
As a figure who was part exuberant salesman, part huckster extraordinaire, part affable best bud, part sage mentor, and part ringleader of a burgeoning new generation of comic nerds, Stan made comics inviting and cool in a way they had never been. The actual comics that came out of the fabled Marvel bullpen (itself another largely fictional creation on Stan's part) of the 1960's were groundbreaking and might have made a sizable impact regardless but I believe it was the personality that Stan projected, the way he was able to imprint himself on those books, that elevated the entire Marvel brand.
Through his Bullpen Bulletins, through his Stan's Soapbox columns, through his many public appearances, through the warm, welcoming, enthusiastic forwards to the many collected editions of Marvel stories, through his distinctive voice work in Marvel's animated endeavors ("Stan Lee here!"), Stan gave a generation of comic fans someone they could think of as their friend. Not just a friend, a but cool friend who invited them to be a part of something bigger than themselves. Thanks to Stan, comic fans weren't just lonely nerds enjoying the adventures of their favorite superheroes, they were part of the Merry Marvel Marching Society, they were Friends of ol' Marvel, they were True Believers. Through the effortless exuberance of his public persona, Stan was able to bring fans in and keep them in. Fans wanted to be a part of his world and his world was Marvel.
Long after he stopped scripting the books, long after he no longer had any editorial duties and was not involved in any of the actual production of Marvel Comics, his personality remained indelibly stamped on them for all time. They weren't his anymore but yet somehow they were his forever.
He was the Godfather of the world that all these characters lived in, even the ones that were created by other hands, long after he had left. Had he not been able to create the persona he was known for, had it not been so intractable from Marvel itself, not only would we not remember Stan as we do today but Marvel Comics themselves and the world they embody would surely not have the massive profile that they do.