Pre-Crisis Superman vs. Post-Heroes Reborn Savage Hulk
Superman would be crushed by the Hulk. Superman, or any other DC superhero, has no strength level chart, and he has never shown an act of strength greater than that of the Hulk (Please do NOT give me the moving the moon argument. Superman did not have the force of gravity, or any force resisting him when he moved it. Hulk shattered an asteroid twice the size of the earth in space with a punch.) It is then safe to assume that Hulk is stronger than Superman.
Superman would get crushed. Superman draws his energy from the sun. Hulk could pummel him through the earth's crust, there he couldn't absorb any solar energy. Then, Hulk would commence beating the daylights out of him, similar to the manner in which Darksied did.
People often underestimate Hulk's speed, strength, durability, and battle cunning. Hulk isn't nearly as fast as Superman, nor can he fly. (Note: Superman can NOT, I repeat, can NOT move at the speed of light! He can only fly, not run, slightly faster than the speed of sound.) However he is certainly not slow by any means. Hulk can run much faster than any sort of automobile and has a jumping ability greater than anyone; He can leap into space in a single bound.
Hulk is also insanely strong. His strength is limitless, thus there is nothing that he cannot destroy, Superman included. During the Secret Wars, Hulk carried a 150,000,000,000 ton mountain. Superman has never displayed a feat of such strength. May I remind you, this was not his limit of strength, as there is no upper limit to his might.
Hulk's regeneration factor is greater than anyone in the Marvel universe, including Wolverine. He once regenerated from a virtual skeleton in minutes. Even if Superman wanted to kill (or was capable of killing) Hulk, it would be impossible to do so.
Hulk has no weaknesses for Superman to exploit (his only weakness being his mind and gullibility). Superman has three very exploitable weaknesses, Kryptonite, Magic, and deprivation of Sunlight. If Hulk can deprive Superman of sunlight, it's no contest. I understand that Superman is way more popular, but I'm talking about science.
Superman could never beat the Hulk with strength. His only chance would be to calm him down.