The question needs more context, like" "if you could only... to get a good job" "if you could only... to understand the roots of programming" etc..

For example, to have a better understanding of programming I would chose 3 different paradigms: - an object oriented language. eg: Smalltalk - a logic language. eg: Prolog - a functional language. eg: Haskell

But if I would want to get a good job I would chose Java, C# and Objective-C