IK this question has been solved already, but here's my input for noobs:
I prefer Portable Python 2.7 with PyOpenGL and PyGLFW using GLSL (GL 4.0 preferred) for code simplicity.
(use GLSL and make the GPU do most of the work (especially for the draw-code) or otherwize you'll choke your performance with python's interpreter)
C is the best of all, but if you follow todays standards with GL 4.0, it almost doesn't matter what language you use.
the only last stress factor is how your game should work...
for example, a game like Minecraft requires your CPU RAM because gigabytes greatly matter over megabytes, and todays common GPU RAM is about 1GB and can't all be addressed at once, while common CPU RAM is about 4GB.
best interface here is CPU RAM which you'll want C++ (not .NET) for.
(not exactly sure why Notch chose Java here)
.NET though is good for GC (Garbage Collection (Python terms)) or MM (Memory Management)
but Mono is far superior to .NET as it's cross-platform
CPython also fits here to make things about as powerful as C#, but not as messy