i think godzilla will win because of size and power and a whole bunch of facts
1. in all the movies king kong usually dies by machine guns and planes and stuff but that never happened to godzilla.
2.godzilla is like the size of the empire state building and king kong is the size of 2 two story building's
3.godzilla is supposed to be indestructible and king kong is just a oversized monkey
4.you really got to think logic if godzilla loses to a monkey that's really fucked up cause godzilla fights against a bunch of monsters that probably kill king kong in a instint.
so there's just a few fact's and reasons the godzilla would win.