United States of America is probably the most popular country in the world. Nothing surprising in that, cause thanks to the American movies and TV series people all around the world are familiar with the cities in USA.
Typical holidays in tropical country is very nice, but this option is getting less and less popular. Nowadays people are more into sightseeing than tanning, so they prefer to visit places with interesting monuments to explore.
Northern America is one of the most wealthy part of the world, thanks to local countries, United States and Canada. The second place is maybe colder, but also has a lot better reputation.