The countries everyone know something about and most people can easy identify their cultures
Based on population size, economic power, and cultural influence, here are my guesses for the 13 most well-known nations:
United States
China
India
Japan
Russia
Germany
United Kingdom
France
Brazil
Mexico
Canada
Australia
South Korea
Of course, there are many other nations that are well-known for various reasons, and this list could vary depending on the context or criteria used.