This is a little like going to IKEA and saying "I need to furnish my house, what should I buy"? Without knowing more about the intended use of the language, it's hard to give a good answer. However, if pressed, I would say Javascript. It starts simple (but is not a simple language), you can build slick web pages with it, and you can even build native mobile apps for Android and iPhone (e.g. with using PhoneGap).
I don't have a specific app idea in mind for which I want to learn programming. Mostly, I like consumer web apps, and which may require integration with facebook, twitter APIs. I'm not looking to build a full blown app myself - rather a quick prototype to test it out with users and if there's traction, then it would make sense for me to team up with engineers and build it out. Regarding Javascript - as you say, I too…
If you are a little more serious in your desire to learn programming, than you can learn Java. That way, you can go the GWT route when you need Javascript functionality.