Well, Superman can fly, Hulk can't. That means Superman will always win, imply because he can do the one thing that always works against the Hulk, remove him from the battlefield. I don't think either of them can kill the other, but Superman has options Hulk does not. That or he could just kiss Hulk and make him forget why he's angry in the first place. Seriously though, why does Superman have a mind erasing kiss?

If it wasn't for the ol' "Superman can throw him in a black hole" cop out, Hulk would have a lot more of a shot. If you limit the fight to earth, Hulk wins.

Pretty easy to work out. Hulk may have basically limitless strength, but no matter what incarnation of superman we look at, he's got more speed and maneuverability than Hulk could ever hope to reach. If Supes could hold him long enough, he could either toss him into the sun or, toss him in any direction into space. Hulk don't do so well in space, so he would be at the mercy of whatever body of gravity he came too close too in his floating voyage.