If you're interested in learning how to program simple games i would definitely recommend
http://processing.org. The language is written in Java and it really is just Java, but makes it extremely easy to design visual effects or games and is an amazing language for starting learning object oriented programming and other topics.
So far C and Java have been suggested. I personally like Java more due to its much more visually appealing code, simplicity, and a lot because of my experience with it. C is technically more powerful but that's definitely not something you need to concern yourself with for programming simple games. C is 'lower level' (closer to the hardware) than Java, and is the closest most programmers ever get to the hardware. Java itself was written in C. If you do decide to choose the C path, I recommend starting with C and not C++ for multiple reasons which you can probably just look up. C# is a whole different story and a language you might see combined with Unity to create fully fledged modern FPS games. Although as already stated, Java is technically 'slower' than C because the code isn't directly compiled into machine language but bytecode which is then run, for games created by anyone less than big companies, its not much of a concern. This is actually one of the greatest advantages of Java because it makes the language platform independent (the same code will run on any machine which has Java installed) which is an advantage C languages do not have. "Slower code" should be of very little concern, your game is not going to be laggy just because its not being directly processed by the computer. See this stackoverflow question
http://bit.ly/1qoheWK if you want some more information.
Regardless, I still recommend Processing. It takes very little time to learn how to program simple games, but if you want to do more complex stuff then Processing might start to become a bit of a hindrance, but it really wont matter because by then you'll already have a pretty decent grasp of Java
