What a stupid discussion.
Godzilla obviously. Godzilla has the same endurance that Cloverfield has or possibly even more. Cloverfield only has his little critters as bonus attack, but that is worthless against Godzilla. Godzilla has nuclear breath, which would damage Cloverfield.
Besides, Cloverfields biological structure is retarded. His arms are longer than his legs, that is not good for hit and run tactics, which Godzilla could apply to Cloverfield... if he was a pussy, which Godzilla is not.
Basically, Godzilla is Cloverfield but with a much more intelligent biological design plus nuclear breath. I don`t see how Cloverfield can win. Besides, Cloverfields breathing system is external (he has his breathing sacks outside) Godzilla could just nuclear-breath upon them and kill him.