I believe that kratos would win in a fight against goku because he beat all the other Greek gods and took there powers. What ever you threw at him he would just take and throw it right back at you He defeated Zeus , Poseidon, Hates, Hermes, ever single opponent you threw at him. He even defeated himself in ghost of Sparta and even killed his own brother Kratos is a force of destruction that can't be beating.
I'll be clear. I am not a DBZ fan, but I know enough about it to see why he would win this fight. I call it the Superman Dilemma. Goku has the power to casually destroy planets. He became immortal by the end of the series, at least immeasurably powerful. It's not which is better, its simple measures of power. Goku is far more powerful, and would simply boot Kratos into space with his first kick.