Programming Language

One of the toughest choices for me nowadays is figuring out which programming language to start a project in. The main options that come to mind are C#, Java or C++. I guess it is only fair to see which one would be the most productive. Java is wonderful in that it supports cross-platform development, easy-to-use and many great free tools. C# on the other hand also supports cross-platform, but for the purposes of the projects projects I have in mind this would be limited to Windows, Xbox or Win7 Phone. Just something to think about.