Goku would Crush Superman in a duel....

Okay, allow me to tap into my super nerdiness so I can legtimately answer this question....

The fight would clearly end in a stalemate. Superman is impenetrable to everything except kryptonite. That includes super mega blasts, laser beams, and kamehamehas. So unless Goku uses the dragonballs and wishes for some krytonite, he would not be able to kill him no matter how strong. And Superman is not strong enough physically to beat Goku. In fact, the more he tried to damage him, Goku would just eventually get stronger from it. Therefore stalemate all the way. No one would win and in the end they would end up being buddies because they are both good guys.

Whoa! Okay, I'm back. What just happened...