I'm in no sense of the word an expert or authority on the matter as i don't know much about programming myself, i'm learning at the moment...
but, just for my two cents, i think this isn't something everyone wants to just answer because it really depends on the context.. it depends on what your planning on developing and for what...
as an example if your going to be doing web applications then i think PHP is starting to become extremely popular,
off the web it gets a little more complex, depending on OS, Portability, and some other factors...
I believe C# is mainly for microsoft systems as a major component in it is .net
C++ is as you probably know an offspring of C and is a general programming language, out of the three you have listed its probably the most popular...
Java to me is kinda like C#'s older brother, same basic structure i beleive, but without the .net, so if your trying to branch off from mmicrosoft it would be the better choice...
once again, these are more my opinions than anything, and you may want to wait for someone more knowledgable on the subject to swing through...