personaly I like more Goku as a hero than superman, but I'd have to agree that superman would win.
goku would never use kriptonite to weaken superman, it's not in his nature, Goku likes to fight people stronger than him, and would never use such a dirty trick.
secondly, Goku does have his limits, and while both of them would have a good fight at first, Goku is not invinsible (and neither is superman anyway), but superman can stand anyhting that Goku throws at him for longer than Goku would.
Also, if goku dies, yes, he can be revived with the dragon balls, but in the meantime superman might recover his strength thanks to the sun, and the battle would go agin, lasting a bit longer this time since Goku became more powerful, but in the end, he would die again, and not enough time would have passed so that the spheres can be used again.
anyway, I think it comes to this: they are both "good guys", and would never really fight each other, only way they would is if they get into one of those situations in which they have to fight or everybody in the planet dies type of thing.
oh, and please, if you don't like anime, manga or anything like it, please express your opinion without having to insult everybody for liking it, or calling the characters gay, or fag, or whatever, stop the violence man, there's enough of it out there in the real world.
peace.