C# isn't just for Microsoft development. I do game development with it using the Unity3d engine. Other game engines also support it, like the unreal engine. Unity can quickly compile your game to work with any platform, so this idea that C# is only a microsoft thing is quickly evaporating, thanks to projects like monodevelop.

I would agree that python is a great language, but really, you just need to learn one in order to understand the concepts. When you are just starting out, one is just as good as the others. Once you understand the concepts, picking up another language is much easier.