Originally Posted by medtech_expat
Am surprised this wasn't mentioned til post 11.
To the OP - if your motivation to learn a language is primarily personal interest, I'd stick with one of the Latin derivatives. You get Roman letters (unlike Russian or Arabic), you get an alphabet (unlike Madarin), and if you attain a certain fluency in one you can pretty much understand and be understood in most of the others.
Spanish will give you upside with Italian and Portuguese, so it's a 3-fer. If you're not interested in Spanish, try Italian - which is always fun, and Italians love whomever makes even a modest attempt at their language.
On the other hand, if by "useful" you mean the ability to communicate with the most number of people, then you're back to Mandarin.
well you don't really need to learn Chinese characters to learn Mandarin.
I learned it pin yin, and was conversationally pretty decent way-back-when (I've basically forgotten it all now), but on the whole: plus one to the people saying Mandarin and plus one to the people saying "you need Chinese for business in China". Yes, you will get by without it, yes, a lot of people will speak to you in English, and then they will turn and confer with their colleagues, and you will have no idea what they are saying. This is not ideal.