Depends what I'm trying to do. Python's usually the quickest language for me to turn something around, though I've used some weird languages specific to software (i.e. autohotkey).
I've seen a lot of job posts recently for Angular, Javascript, NodeJS, Ruby on Rails, etc; so if you're looking at the "hottest" languages in the market right now I'd say those. Unless you're looking into Machine Learning in which case Python has a ton of support for it.
Interestingly enough, MatLab also has some ML tools...