I've got to vote for Japan, there are quite of few anime and manga that have cosmic level heroes based there, and there are just so many of them.
The main series to look out for would be:
Tenchi Muyo
Meloncholy of Haruhi Suzumiya
RahXephon
Neon Genesis Evangelion
all of them possess heroes capable of at least planetary scale reality warping.
Originally posted by {{QS}}
New York could declare itself independent in this War, they've got way too many heroes.Also I've always seen it as Metropolis = New York (Yes I know its supposed to be in Kansas but its skyline and stuff emulates New York) and Gotham = Detroit.
Gotham and Metropolis are both visually and aesthetically based on New York (by the way, originally, Metropolis was based off Toronto, but that's long ago): "Batman's Gotham City is Manhattan below Fourteenth Street at eleven minutes past midnight on the coldest night in November." Denny O'Neil, who edited Batman for longer than well... anyone.
Metropolis, by the way, is apparently in Delaware.
And New York exists as a separate place entirely. It's where the Justice Society lives.