Since Thor has been "hulked" out his one weakness is his uncontrollable rage/diminished intelligence, the more angry the less he'll have control over his hammer as it will deem him unworthy until he calms down as it happened in Fall of the Hulks. Goku,Vegeta,and Gohan can exploit this weakness giving them a slight advantage over the battle, but Thor is quite formidable without his hammer.
I'm going to say Thor because ordinary Thor is already FTL, strong enough to shatter planets and move the World Serpent, and durable enough to survive in the core of the Sun unscathed, not to mention all the powers that Mjolnir grant him are insane, such as the absorption of the Earth's entire electromagnetic field into it, the matter transmutation and massive energy projection e.g Godblast. A hulked out Thor will simply be far too strong and physically imposing, it's basically Thor with all his powers plus the Hulk's strength and durability combined with his own. Way too much power. And nobody here except Goku can even contend with Thor's speed because none are FTL except Goku with IT.
I think DBZ character are capable of keeping with Thor in Speed, this treat has lots of info regarding Speed: http://www.animevice.com/dragon-ball/10-1/how-fast-are-dbz-characters/97-314493/?page=7
The OP hasn't really stated with powers the DBZ fighter are are they Mystic/SSJ3/SSJ2. If i'm not mistaken the Classic Thor could lift up the Midgard Serpent and do all those other crazy stuff but are we using Classic Thor or current.
@niBBit: The Z-fighters are all at their peaks during this battle.
@Newdeath: Sorry, I wasn't being very specific about the side effects mostly meant the whole dying in couple hours of being exposed to such a high amount of energy. I wouldn't count being less intelligent/enraged as an ill side effect its pretty much a given since hes a hulk he'll have some tendencies of being easily angered and the hammer will disobey him like it was during the events of Fall of the hulks.
Besides pointing out gamma radiation pouring into Thor will do absolutely nothing to him, after a bloodlusted Thor throws his hammer the Z-fighters will find mjolnir sized holes through their chests like butter. Thor isn't just stronger or more durable than them, hes WAY STRONGER AND WAY MORE DURABLE. Making him go out for blood just makes him more likely to do what he did against the Angrir, despite not wanting to kill him, he still plowed a hole through his chest with Mjolnir.
@MisterShin: Thor is fast enough to blitz Goku before he can use IT. He blitzed SS recently.
Broly did it over time, which is why there was a surviving planet for Goku to look for Broly's ki.
Nothing in the anime suggests they can match Thor's level of power. And their energy attacks can just be absorbed into Mjolnir since he's already absorbed the energy from a bomb that was going to destroy an entire galaxy.