It sounds like you're looking to feed confirmation bias. Picking a country that most Americans love to hate isn't really going to give you accurate results. Try comparing the U.S. to Germany and Switzerland, or the U.S. to the Scandinavian countries.
Also, keep in mind that statistics on emigration only show you how many people moved between the countries. It doesn't show you whether people in Germany are more likely to be curious about the U.S. than vice versa, or whether the people are happier and have more freedom.
I am a European living in the U.S., and I agree the U.S. is a terrific country to be in if you are making a lot of money. But most people don't. The poor here are far worse off (and the rich are far better off--indeed, that is the definition of inequality.)