You think Gokus punches won?t hurt him?
http://www.youtube.com/watch?v=uklSyanOQfY
Even a mere human can throw him around and make him shout "aahhh".
Another point, Superman is ~ as strong as Darkside, maybe a bit stronger.
Darkside died by the explosion of a small planet =/. I doubt the planet was too big, it had the shape of a head ;/ .
Goku would made minced meat of superman.
I would say:
Goku fighting with his martial arts and using Zanzoken would overpower Superman.
If goku uses Kaiokken to power up --> Superman = minced meat. If Goku shoots him with a Kame --> Superman = minced meat.
If goku throws a Kienzan --> Superman = cut in half
If Goku uses Renzoku Kikou Dan --> Superman = badly hurt
If Goku ueses Ryū-Ken --> Superman = Dead
If Goku don?t use any of this attacks or just don?t success hitting superman, then Supermans next action would be to fly directly to the sun to powerup.
Goku don?t know anything about Superman, so he don?t care if superman flys to the sun and power up. Superman is coming back as SuperSuperman. Goku feels his strong KI (YES he can feel Supermans KI. Superman is getting his power from the sun, so he possess a great amount of power. And Goku can feel this power. Just because the power superman has isn?t coming from his own strength but from the sun, doesn?t change the fact that he still possess this powers. The source just differs in this case) and so Goku transform to SSJ. The fight starts from the beginning. Goku overpowers Superman with Zanzoken again.
Superman gets hit here and there, Goku uses the opportunity and burns superman to super-roast-man with a Kamehameha.
End of story, Goku wins.
EDIT: SaiyanPride...
Goku fought enemys who survived a planet explosion and won =/.
Goku fought enemys who survived a direct attack which could destroy a planet and he won.
In whole DBZ he never got hit by 1 of those planet destroying attacks directly, because he was fighting awesome.
I have to come to the conclusion that he was stronger than his opponents, because he definitely beaten them.
Friezas attacks which would probably kill frieza himself if he gets directly hit, didn?t even hurt Goku SSJ.
Frieza survived the explosion of namek.
Goku SSJ punches were still to hard for him and would have kill him.
Goku SSJ >> Frieza in everything!
Gokus SSJ1 later was WAY WAY stronger than when he fought frieza
Goku can go SSJ2
Goku can go SSJ3
You are completely wrong about the shockwaves. There are explosion waves, there even are aura waves and air waves which cuts through rock when the punch of goku miss.
EDIT 2:
Goku blocked planet destroying attacks with his bare hands.
Even in DB when he fought Piccolo in the Budokai, he didn?t die by piccolos destructive attack which destroyed the whole island [the island was big]. (he blocked the attack with his bare hands)
And Goku at the end of DBZ in his normal form is >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> than Goku at the end of DB
EDIT 3:
Superman don?t even possess an attack which can scratch a planet =/.