If we as a species could bring only one person back to life, for whom would you vote to bring back?

I understand that everyone has a certain loved one that they would want to see again, but thats not what I am asking about. If you were trying to pick the person who would have the most positive effect on society,(like an inventor or scientist or leader or whatever) who would you pick?

Oh, and in this hypothetic situation we can bring back anyone from any point in history, no matter how decomposed they are and they will just as pretty as they were when they were alive.