I often discus game development on the Steam chat with game developers. Unity is a .NET framework platform which relatively popular. Most questions are C# related.
the id tech engine is openGL based and while C++ at the core there is a meta language to make game animation easier
the unreal engine is not widely used due to the steep learning curve. the crytek engine is also rather steep. both also are relatively expensive so only larger shops tend to use them
lua is a growing language for game engines and should it become stronger it may well become the latest game middleware
if course you can roll your own with ray casting and clone Doom and have some fun, not more than 5,000 lines of code is needed
