In terms of actual real-world tangible importance, I consider Alan Turing more important than Einstein. He and von Neumann are possibly the greatest scientists

In terms of actual real-world tangible importance, I consider Alan Turing more important than Einstein. He and von Neumann are possibly the greatest scientists of the 20th century. BTW, another thing people often don't know about Turing and von Neumann was that their interests went beyond computers and mathematics. Both were very interested in biology and physics as well, and did important work on those fields. von Neumann in particular did important work in regard to the theory of self-replication, early proto-evolutionary-information-theory, etc.