From Hulk Movie Board:
In Electronic Gaming Monthly magazine Oct 2006 issues, Stan Lee was asked his opinion about Hulk vs Superman and this is what he wrote, "If I wrote the story, I guarantee the Hulk would win. The way I established the Hulk, the more he fought, the stronger he got. And Superman has a certain amount of strength and thats it. I assume at some point he'll get worn out, but never the Hulk."
In Electronic Gaming Monthly magazine Oct 2006 issues, Stan Lee was asked his opinion about Hulk vs Superman and this is what he wrote, "If I wrote the story, I guarantee the Hulk would win. The way I established the Hulk, the more he fought, the stronger he got. And Superman has a certain amount of strength and thats it. I assume at some point he'll get worn out, but never the Hulk."