I've chosen Chinese.
Mainly if you wanna work with international business.
English is already the most useful language, but I believe that in the next years Chinese will be a very important language.
I live in a port city and over here, if you wanna a great job, it's good that you know Chinese. China is our major client and people that works in the Port also say that Chineses don't like to make business speaking in English.
That's my opinion. English always will be the most useful language in general, but in the world business, I bet in Chinese.