These days Hulk is clearly written has being stronger than Thor. On the other hand, Thor has shown to be more powerfull than Hulk. And I think everyone should be ok with that. After all if you take Hulk's strength thing away, what's left of him?????
Truth is in optimal conditions, with no PIS, CIS or cheapshots (and even with those) each character has only 1 victory over the other where they were both actually koed..