If you actually do the research Goku wins. At his base form Goku would lose. But he gets stronger every time he gets his ass beat. Considering both are good guys, neither one would kill the other. So Superman would beat up Goku. Goku would live, get stronger thanks to his Saiyan blood, go train, and try again. I feel that Superman would win again. Same process. Goku would lose at least one more time and the same process would occur again. After this point Goku would win every time. If they were to fight based off all the knowledge of each at this point in history, Goku would win (a Super Saiyan God Super Saiyan that continues to train fighting the Man of Steel whose heat vision and freeze breath would have no effect whatsoever)