von Neumann's body of work is so impressive.

Anyone unfamiliar with him should at least glance at this Known For section on Wikipedia. https://en.wikipedia.org/wiki/John_von_Neumann

His body of work, breadth of scope, and reach of influence is really only comparable to Newton, Gauss, or Euler.

Edit: Can't forget Gauss.

Neumann is definitely the last true polymath, and in my opinion the greatest scientist of the 20th century. Coincidentally, I named my new PC at the university "vneumann" yesterday.

Don't forget Gauss - he has more contributions than any you've listed, and contributed to a vast number of fields. His 'known for' section is a separate Wikipedia page ;)