Any language, but try to learn about culture too (Score 1)

If you choose a language which associated culture is very differente from yours, better you'll think out of the box. For example, I'm brazilian and besides learning English, I'm learning Japanese and Mandarin. To understand why japanese or chinese people use some words sometimes, I have to learn about the culture. I think it's true for every language, but Japanese culture is more far from mine than American culture, for example. And I'm convicted that learning how different people think can expand my mind.