And part of that is the depth of what he's done. And part of that is the breadth of what he's done. And part of that is length of time he's been doing this (that) shit: his first story as a writer was in 1941. It's unclear to me how involved he is currently in the myriad of projects he's started, but I think it's safe to say that at 88 he's almost as active as my Nana.
[By the way, all of this is brazenly cribbed from his Wikipedia entry (here).] Lee can be credited with evolving the super hero comic genre from a "white hat" hero simplicity to a more sophisticated mythology. After DC's Silver Age launched and the Justice League became a hot title, Lee was assigned to create a new super hero team for Marvel. His wife pushed him to play with writing styles he liked.
Lee gave "his superheroes a flawed humanity, a change from the ideal archetypes that were typically written for pre-teens. His heroes could have bad tempers, melancholy fits, vanity, greed, etc. They bickered amongst themselves, worried about paying their bills and impressing girlfriends, and even were sometimes physically ill. Before him, most superheroes were idealistically perfect people with no serious, lasting problems."With Lee as Editor-in-Chief, Marvel in the 60s is compared to the French New Wave in terms of how radically the style of storytelling changed. But where the New Wave movement shifted power in the film world from studios to directors, Lee the editor and publisher put/kept Marvel's interests ahead of its writers and artists (and if it sounds like I'm being critical of that, in fact I'm affirming that dude did the right thing--it's something of an emotional issue that people who create classic characters like Batman and Dazzler don't own those characters, the giant publishing company does... no shit, you mean the people who hired you to do a job expect you to do that job? you don't hear about people at the GMC factory complaining that they don't own all those pick-up trucks they helped make).
Granted, putting Marvel's interest first effectively put Stan Lee first, since he has been THE face of Marvel for longer than I have been alive (which, officially, is only like 32 years, with an undisclosed margin of error). But I think Lee personifying the Marvel Comics universe is actually inspired--I don't know if it's something he would have done any way, or if it made sense to him, from an editorial perspective, to give readers someone with some authority who could listen to their complaints and suggestions. There are 7 or 8 names of people from the 70s and 80s who wielded a lot of creative control in the comics business (Jim Shooter, Julius Schwartz, Marv Wolfman, and Roy Thomas come to mind, but I'm sure I'm ignoring some really obvious names) and I'd bet a substantial amount of money that 95% of comics fans can only really tell you about Lee. Even if all Lee did was put his face next to the work of 5 or 6 anonymous writers and editors who operated in a uniform style, that's genius enough, if only to serve as a lightning rod for bitter fanboys. Not that I'm bitter, or a fanboy... hey, let's watch some movie clips!
Happy birthday dude! Rock on!