That will depend on what you want to do. For Windows-based programming, I agree with Sam. C# is the way to go. As an alternative, VB.Net would be a decent choice (and probably easier for you, since you have VB/VBA experience already).
If you want to do other types of programming, take a look at what languages are commonly used in your area for the type of work you want to do.
I'm not on the WHS team, I just post a lot. :)