closed as off topic by yannis May 31 '12 at 7:05
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For windows automation I use Powershell a lot. It doesn't feel much like a real language ( maybe Perl, a touch ) and you wouldn't use it to write applications, but it really is very handy for automating things in Windows that you need to automate, and as it can reach into .net it can actually do a lot of clever things with your system- more than you might expect.
If you want to learn something for fun then maybe start with Ruby. It's flexible, expressive and powerful but mostly it is an absolute pleasure to program with.
General purpose? Then either Python or Perl. I'd say the latter was more used but it doesn't really matter, just pick one of the two and go with it!