I suggest to start with the C for knowing the basic criteria of the language.It gives a path how to climb on the hill. Then you will try some more go with C++,Java. Both languages C++ and JAVA are essential blood of the programming.
Are u perfect with programming language in C,C++,JAVA.
More advanced uses the C#.NET with framework 2.0.This language enchances the knowledge to some different view.Also, Make self projects with all the language.When you face the problem u got a perfect solution and implement in the future.