[Avshalom]

While their practical achievements have had tremendous affect on a specific level of a revolutionary industry: Von Neumann alone was smarter and more influential than any three of them combined (maybe excluding Shannon).

To be fair that's also true of almost any three people involved in the Manhattan Project too.

[di4na]

Not a maybe for Shannon. He is still having a trememdous impact. Information theory has developed by Shannon is so fundamental that we forget about it these days. But big.

I could argue for Shockley and Hamming, but they were more on an engineering side.