I suppose I would say New York. It is one of the largest financial cities in the world and the large city in the world in terms of skyscrapers. Plus the statue of liberty is a visually stunning sight to see. Yeah, I must say New York. It is just a wondrous sight at day or night. 

 Tokyo or London are good choices too.

 I think the Capital Of the World Should be a city with low population, but with high natural things like trees, animals and birds and lakes and rivers

That will inspire people to save nature!!

 I'd say London. Its one of the financial capitals of the world, its right in the middle of most world maps and it was historically the worlds capital for a long time. I'd go with London, its a nice city too, big, but with a lot of green space. Good landmarks too. Also time, at least where I am from is measured from London (GMT).