What should I learn?

I'm a 21 year old American looking to expand my language horizons. I took two years of Spanish in high school I remember bits and pieces. I could remember more if you dropped me in a Spanish speaking country but it would only be basics. I want to learn a secondary language, but not Spanish as I could get by fairly well if I needed to.

I'd like to be semi-fluent in a fairly easy to learn language. What would you folks suggest?