C++ is among the top of the widely used languages for games. It retains the quick execution speed of C, and brings in much needed and required things such as objects and class inheritance (OOP). Naturally, you'd be using graphics libraries with this, such as OpenGL or DirectX. Possibly even also pre-made engines (Unreal, Crytek, etc.) if you have the hundreds to thousands of dollars.
Programming language aside, you'll also need a very strong understanding of advanced mathematics, for 3D math.
C++ is the main one used for gaming, but I have a feeling soon enough it'll move to C#. Anyway here are some subjects I've taken that you'd need.
1) C++ (beginner, int. , advanced)
2) C++ Data Structures
3) Game Dev (w/ either DirectX or OpenGL) Prefer DirectX
4) College Algebra I & II
6) Linear Algebra
7) Discrete Mathematics
9) AI Dev.
Just to name a few. Oh and most importantly patience and lots of it.
I also have a keen interest in game designing. I would suggest you to learn graphics under c if you know C language. Its very easy if you know C language, I myself learned it with help of a book "Graphics under C by Yashwant Karnetkar" . I have tried some simple games like snake xenia , bricks, packman and learned a lot. Try learning this language I'm sure you will find it interesting.