Back then it would have been an interesting fight but now a days where the limits of Ben's powers and the limitlessness of Bruces powers have been explored there is no way the Hulk would loose, at least against the Thing alone.
The Thing is increadibly tough but his strength is still finite. The Hulk's strength grows in proportion to his anger so there's no way Thing could stand up against Hulk unless he some how gets lucky and knocks Hulk out early.
I'd really like to see the Hulk throw down with a character like Thanos. You know someone who is far outside the ideas of physical strength (think cosmic powers). I'm sure Hulk would probably come out on top (especially these days) but Thanos would give him a run for his money.