In a way, language choice doesn't matter. There is A LOT more to learning HOW to use a language (analysis, design, patterns, algorithms, etc...) versus learning a language itself. Syntax is relatively easy to master, even with a language as vast as C++, versus the actual working knowledge.
As a simple analogy, it doesn't take the carpenter long to see how to sling a hammer, a chisel and a saw, but building a Chippendale cabinet can take years to master.
But, in order of preference, I would agree with SamuraiCrow and Reedbeta: Python first, C++ second, then maybe C, C# or Lua third.
Python is arguably simpler, but not by much, than C++, and prevalent in the game development world. C++ can be much more complex, but the parts you actually need (vs. admire from a distance) are not much worse than Python. And, it is the most prevalent language in the gaming world.
Lastly, C is obviously popular for historical reasons and/or where performance matters a lot. C# is made popular by Microsoft its push in the game development world, and its large community. And Lua is a popular scripting language similar to Python.