So James Clark Maxwell should be right up there with them.

James Clark Maxwell and his four equations laid the foundations of the modern world Carl Sagan has said. Maxwell's equations are a set of partial differential equations that, together with the Lorentz force law, form the foundation of classical electromagnetism, classical optics, and electric circuits. ... The microscopic Maxwell equations have universal applicability, but are unwieldy for common calculations. Without Maxwell, Nikola Tesla and Albert Einstein would not have been able to begin their reseach and work. .

I'd have to refer you to Newton as well, with his quote ..." If I have seen further than others, it is by standing on the shoulders of others"... Deeper than most give credit. He realized the importance of the contributions of his predecessors, and acknowledged his progress was only because of them... But I chose Tesla?

It's a tough one, I'll get back to you

Nicolaus Copernicus

One's work would not be possible without the other's. I don't think it is a fair question.

But I must say, it would take 1000 of me to do what any of them achieved. If a mass murder didn't start first.

Tesla