Well, Einstein had a few great ideas, not one. Special relativity, general relativity, statistical mechanics, and energy = mass. He only really missed quantum mechanics. Newton and Leibniz come close, but none of his contemporaries.

But it is really off topic. Let's say Einstein and his contemporaries are more important than Bill, the guy who really made DOS, and the first few MS employees, but obviously the later group is a lot wealthier.