What Persian leader made the biggest contribution? Why?

Hi, I think that Darius I made the biggest contribution, basically he was noted for his administrative genius, his great building projects, he conquered the Indus Valley, he undertook a number of campaigns with the purpose of strengthening his frontiers and checking the incursions of nomadic tribes, he did a lot of things, at the end his army was defeated by the Athenians, but still he was the Persian leader that was the one that achieved a lot of things.