If you're wanting to get into development of any sort, then asking "which language do I pick" should not be at the top of your list.
Learning design patterns, complexity modelling, rapid prototyping, formal specifications (code contracts), high integrity development etc, should be the priority. There's a ton of theory work that needs to be done to make you into a decent software engineer. I jumped into development by just going straight into programming stuff, keyboard composing. It was only til later when I started learning best practices at university that I realised the sheer amount of bad habits I had naturally formed. It was a painful process, getting rid of them, and forming better ones. My advice is to not just jump into a language, but do the theory work that applies industry wide. A project with a well designed program (game or otherwise) looks at the code last, no matter the language, since it's the design that matters. It's great that you may have just made a game that runs a few things on different threads. But it's entirely something else to have those threads be memory safe, and created via a factory pattern.
Regardless, if you're wanting to learn a language, then C++ is always a good one. It's pretty popular, well documented, and fast since it compiles to native. It also gives a lot of freedom to learn memory management. As the creator of C++ himself said, "...with C++ it's much harder to shoot yourself in the foot [than it is to do with C], but when you do, you blow your whole leg off.".
If you're after something fast and entirely OO, then try C#. If you're wanting something more for scripting, then try Python. If you're a masochist, try Java.