Hulk is cooler, but superman would definitely win. I don't think you can argue with that, because invincibility is just part of his character. Only exception is if hulk had kryptonite. Then hulk would win.
Hmm Hulk is pretty invincibile.... Especially angrier he gets more stronger he becomes.
So probably a draw.
Yeah, but hulk isn't completely invincible. He's just so powerful that it seems like he is. As long as there's no kryptonite around, superman is just completely invincible.