[Siegmund]

No love for Euler, most prolific of mathematicians?

Most of the others I would name have already been named.

For a short list I am reluctant to include anyone who merely happened to be first to an idea that was "in the air" - I wonder whether anything from Fermi or Feynman or the transistor guys was really more than a few years ahead of its time. In math, Euclid and Gauss are in... but I wouldn't list either Newton or Leibniz, since they both came to the calculus, and their calculus was really just evolutionary from things like Cavalieri's Method for volumns. In music, I would list Beethoven and Wagner, for doing what had not been done before - but not Bach or Mahler, as much as I love their music, it was more backward- than forward-looking so much of the time.

Another nominee from antiquity: Akhenaton, for some very progressive politics and a willingness to turn an old religion upside down. He got killed for his trouble, of course.