I've used all 3 intensively, and let me enlighten you,
C++ if you mainly want to develop AAA title games from scratch. Especially if you want to make a custom game engine. Or use an already available game engine which is written in C++ (Eg: Unreal Engine 4 )
C# for almost anything from mobile (windows phone) apps to enterprise applications.
Don't learn VB, its last stable version was released 18 years ago. Neither any of new language features are available with this language nor will be added anymore. In fact this was my first OOP language and it's good for a beginner to learn basics. But I recommend C# for that purpose now because it keeps evolving.
Your question is very ambiguous , its like asking whether you should buy a car, van or bike without expressing your requirement.
Use below chart and pick what best one for you