Each country is popular with specific things. There is no Complete Perfect Nation, so I think it is better if people will tell what is popular in thier own country, than telling my country is the best, because nobody is asking which country is the best as far as the natural answer will be "my country"

For example,

China - Great Wall

Hong Kong - Disney Land

Egypt - Pyramids

Qatar - The third biggest Gas field in the world

Philippines - Tarsiers

Iraq - was famous with thier Universities, Libraries, Army, Museums...etc, but not anymore after the country was destroyed in the Last War.
...etc

The above are just examples and not a list of popular things in each country.

ThE mOnStEr Is BaCk To BiTe YoU