Lee was the first to create comic book heroes that aren't perfect. They have moral struggles, and they don't always pick the best path. But they keep trying. His characters immediately started to relate with comic book readers, and gave marvel Comics what it needed to get on it's feet. His humor and style of drawing impacted the comic industry so much, that his influence can be seen in comics today.
It is awesome how Marvel continues to honor him, in a complete opposite of that stupid play in which nothing good ever happens called "Death of a Salesman."
Click here to learn about every Stan Lee appearance.