I don't think Iron Man is even close to them? We still have the likes of Wonder Woman and Superman. Sure in this last decade he's been in these billion dollar movies but I think as a brand it still lacks a lot. People like Robert more than they like Ironman itself. I think Batman is unbeatable. He's got the successful and acclaimed movies, the comics, the games, the animated tv shows and movies. Hell, even his villains have standalone stuff: Catwoman, Joker, Harley Quinn. But Spider is probably second for sure.