Being a huge comic fan myself, my opinion at first is that Hulk vrs Superman would be a toss up. I don't think one would always win against the other. I think the deciding factors would be where they were fighting, and what they are fighting over. If they met in the desert and hulk just didn't like supermans face and got into a fight I think both would have 50/50 chance to win give or take a little. If Hulk is trying to reach his girl friend or his best friend, and Superman gets in his way, then Clark will probably get hammered. Supermans value of life would indeed keep him from going full out, but at the same time if Hulk is raging through the city killing and or endangering innocent peoples lives, Superman is less likely to be as easy on him. Aditionaly, if Superman knows how powerful Hulk is, he probably won't hold back much. Superman has already fought Black Adam and confessed that sicne he knows he can take it, he doesn't need to pull any punches. Now, if Hulk was trying to find his girlfriend and Superman was trying to stop Hulk from smashing buildings that could endanger Lois's life, they'd decimate each other and most likely KO one another.