The one that would be most useful for you would be Mexico. It would help you understand the immigration situation and give you facts about Mexico rather than the vague perceptions most Americans have.
Brasil or if you prefer Brazil for one. Argentina and El Salvador and their problems, debt in the first and drug cartels in the second.
Costa Rica. Check it out and I think you will find that it is one great little country.
This, too is Obama's fault. That mongrel idiot.
I have to do a report on one but can't decide which one to choose.