I use a very limited selection of languages - just one of each sort really.
Java - for everyday things. Because it's quite easy, quite fast, quite simple, quite portable, quite powerful. Quiet everything. I realise "quiet" actually means something completely different in American English, so if you would, please look up the British meaning of the word
C++ - to make Java talk to other things, and for no other reason. Other people have more and better reasons to use C++, but I don't.
SQL - because that's how you use databases. This is my "functional" language choice as opposed to "imperative". If I were going to design a component based entity system, I'd start here.
I used to use all sorts of other things in years gone past - a lot of BASIC (which I still rate as being one of the best inventions ever) mostly, in all sorts of different dialects. I used to love Logo, and Forth was interesting from a scientific viewpoint. I've had the pleasure of using Prolog, POP11, Pascal, and Modula-2 too, but found no later use for them that isn't covered by Java, C++, or SQL.
What I'm hoping for in the next 20 years is something that brings together a reasonably pleasant mix of functional and imperative programming to take advantage of massively multicore systems automatically without me having to think too hard.