What sort of robots will you be using? You'll probably want to design your own high-level language for more complex robots, but for simple ones you should learn something already relatively high-level like Python or Ruby (Ruby is about 10000000 times better than other high-level languages).

For something more rigorous, I would choose C++ or Java, or another similar object oriented language. Of the two, C++ is harder to learn, but faster and more efficient. It'll allow you to include assembly language in your code for extra efficiency. Java is a good entry level language for this generation.