Ok, first things first: Superman and Thor. Thor was able to hold his own pretty well because fo Mjolnir. Supes was certainly surprised when he got hit by that thing. Also, characters with magical powers had them enhanced in the DC universe, as magic wa much more powerful there in general. Supes would beat the hulk, and hulk and Juggernaut have gone at it a couple of times. Also, Juggernaut did the dirty deed with She-Hulk. Talk about ultimate Shmoe-dom
Silver Surfer is powerful, but the DC universe heroes operate on a whole nother level power-wise. Very few marvel charcters even approach the power of anyone in the JLA.