If you are sure about pursuing a career in medicine and wish to study at a prestigious foreign medical school, you need to be clear about your priorities in terms of choosing a particular academic sub-stream. This would depend on your interest as well as aptitude. The best foreign medical schools for Americans should have clinical training options that emphasize research and development, primary care or specialty medicine. The course content and practical aspects of each would certainly differ in many ways. That is the reason why your inclination towards researching which schools have successful graduates in your desired specialty should be part of the criteria in deciding where to enroll.
Apart from that, you also need to analyze the amount of pressure that is going to be in every program and honestly understand if you are ready to deal with the same by discussing with current medical students and graduates. Once that is settled, it is also important that you get a fair idea of how well-equipped the school is in terms of teaching your chosen discipline. The faculty, their attitude, the required number of facilities and resources along with regular examinations of what is taught should all be taken into consideration when you are deciding which institute to apply.