Good question..but..
I'd say DC Thor.(There was that story where her and Kal ended up in Asgard for Ragnarok that took place over about a 100 years or something..) And Marvel Thor seemed to take quite a shine to Wonderwoman, so I'd hope he never clocked her with his hammer. (And by hammer I mean Mjolnir..not y'know..)
Still if you look really closely in the background of the Captain America/Batman fight in JLA/Avengers you can see Thor and Wonderwoman 'having at it' so I suppose it's possible. But I'd like to think that Marvel Thor would be gallant enough to never strike a woman unless he absolutely has to:- i.e In some life or Death situation.(Check out his 'fight' with Storm in the 2nd Contest of Champions mini series for a good example of Thor's old fashioned would be chivalry there..)
Which of course would probably get him a few bruises from Wonderwoman..(Something which I sure his pal Herc could testify to..)