Metro should win. Even his smallest incarnation has about 300 feet on Big G. 355(Godzilla) vs 698(Metroplex). Also he's so tough you need low yield nukes to even scratch his armor. And he's ya know a city turned into a robot. He's huge to the upwards of 100 foot robots who walk around in him as a city. And his weapons are are big amd powerful as he is.
