Hulk has durability superior to Wonder Woman. He has a far superior ability to sustain damage and keep on going. He also has a noticeably superior healing factor.
In what sense? Stacking her durability with the bracers? She uses them to block often enough and they have a higher indestructibility than Hulk's skin, but in plenty of situations, they have been circumvented. If I had to pick whether to have Wonder Woman durability + bracers or the Hulk's, I'll take the Hulk's all day.
They both have significant damage soak, and have taken major hits from top-tier powerhouses. They are also both top tier power houses themselves.
As for which character has greater damage soak, I would have to say the Hulk.
Now, Diana has crazy effective damage soak. An example clearly seen when she was fighting a crazed Superman, and he punched her from near the Sun all the way to earth ...and she was up. She has been hit by all sort of characters, and even taken point blank HV from the same crazed Superman. She’s an absolute beast.
On the other hand, we have seen alternate versions of Hulk knocked out ...including by a Superman analogue (Sun God).
But why do I say the Hulk?
Two reasons - one he has a major healing factor that will augment his already high damage soak, and secondly Diana has that piercing weapon inconsistency that just messes up what would otherwise be a highest-of-high-tier damage soak.
If Diana didn’t have that pesky piercing weapon inconsistency, I’d rethink my decision. For now though, the Hulk.
But that’s exactly the problem SSJGG ...the piercing weakness is a big issue for Diana. Don’t get me wrong - in terms of blunt force durability, she has been consistently written as being able to work with the big boys. The piercing vulnerability however means that questions arise ...for example, what would happen if someone placed a .44 magnum to her head and pulled the trigger? It’s a real question, and while I doubt it would kill her it is STILL a big question.
I do know at least one alternate version of Diana is shown as being completely proof (rounds bouncing off her face), but unlike other characters the mainstream version of Diana has consistently been shown as having to block bullets and arrows. Compared to virtually everyone else on the JLA, with the exception of Bruce, who is shown as being bullet proof. Even Aquaman has been shown has simply getting a cut from a high-powered rifle round to the face!
That piercing vulnerability becomes confusing once you consider (1) she’s taken some crazy hits from the likes of Kal and Darkseid, and (2) she has talent devastating hits ...eg a point blank nuclear strike when Kal used her sword to cut an atom at an old nuclear power plant.
Crazy that a character who can tank hits from the sun to earth, and survive nuclear detonations, has to worry about arrowheads and .22s
A problematic spillover from the Golden Age of comics that DC has apparently never bothered addressing.