What is the best language to learn?

I live in the Philippines. My batch got the choice to pick these foreign languages. Spanish, Japanese, Chinese and French. I'm planning to become a doctor, and plan to do medical missions worldwide. My highest interests are on French, because I just love France! If I focus more on businesses, my dad said I'd have to do Japanese or Chinese. But I heard Spanish is the most useful if you live in the US, and my family is planning to move there for my college. But please, correct me. I might be dreaming too much. But when I have to pick my choice by the time I get to high school, I have no time. Thanks guys!