Every programming language may add new experiences to your professional knowledge. You get to see new ways of thinking, muti-paradigm solutions which is essential to your development as a professional. Also languages are like tools – the more you know, the better chances you have to do any kind of work you come across. Some of my (subjectively!) favourite languages:
- Haskell – seriously, give this one a shot. It’s not easy but it will just blow your mind when you start understanding things!