I always loved ANSI C for home projects. It's fast and has a lot of tricks to make it quick (pointers for instance). That makes me feel cool :P
I've been working on C++ for half a year now. For game development its the most used language. Why? Many people master it, and the games have huge code bases of C++ code. So maybe some would switch to C#, but Java?
Java is slow my friend:
Java vs. C++
Nine Language Performance Round-up: Benchmarking Math & File I/O
Since C is not managable for large projects (hardly), so I moved to C++. It's nice, especially to make things public (you can easily use it in new projects because of the classes) or to work with in a team.
I'm sure C# is a good alternative, though its build for windows, so making it portable would never be as fast as intended. Also, I guess C# isn't open-source, which is a huge disadvantage on most fronts.
Don't ever start with .NET