One thing Superman is, is FAST. I'm not going to get into a huge fight about who'd beat who (notoriously the some of the dumbest fights ever) but I will say that DBZ guys need more than 10 episodes to move.
There are also lots of continuities of Superman. Some are stronger than others. I don't know about Silver Surfer, but DC and Marvel have done plenty of cross-overs. In one scene, Superman is fighting Thor when he stops Thor's hammer blow with one hand, punches him out with the other, gets up and says, "Might be...the most single-handedly...hardest...thing...I've ever done..." YOU JUST ****ING STOPPED HIS HAMMER WITH ONE HAND. THAT ISN'T HARD.
The moral of the story is, if they ever did a Superman/Silver Surfer fight, neither would win, because the two comics are too busy pussyfooting around and kissing eachother's asses.
Now Superman/Hulk...that would be interesting because Hulk shares many of the same characteristics with Doomsday, the mofo that killed Superman in the 90's or 80's or whatever.