I moved on to a language called PureBasic from gamemaker... I used it to create DLL files for gamemaker. It is a procedural language so it will take a while to learn the concepts required to make games with it. But it is also very easy, amazingly powerful and will teach you more about programming than anything else you could move to.
Well, for example, there's Multimedia Fusion. I've never used it personally, but I've heard good things.I believe Foreshadower knows a lot about it, you should ask him.I'm sure there are other tools as well.