So I could be cheeky and say you should read the book (well you should) but let's see...

-the 'von Neumann architecture', which is the basis for nearly all stored program computers today, from smartphone to laptop. I'm convinced by historian Thomas Haigh's [work](https://www.tomandmaria.com/Tom/Home) which suggests that JVN was uniquely well placed to come up with the design, manage the various players involved and bring in the cash to do it

-game theory and expected utility theory. JVN didn't live long enough to get the Nobel for it (he'd been dead 40 years by the time Nash, Selten and Harsanyi picked up the first Nobel for game theory. But his proof of the minimax theorem birthed the whole field, and his book with Morgenstern, 'Theory of Games and Economic Behaviour' is the canonical text. Game theory makes Internet firms billions through keyword auctions and other ways. It's also key to thinking about nuclear strategy and expected utility theory is central to behavioural economics

-theory of self-replicating automata. by proving mathematically that machines couldd reproduce, von Neumann inspired the first nanotech pioneers as well as legions of science fiction writers and dreamers (von Neumann probes, self-replicating lunar bases).

-he designed the implosion bomb, Fat Man. He then carried out the first computer simulations ever (sadly, they were to help design better bombs and keep the USA ahead in the arms race). Later, he led the team that carried out the first computerised weather forecast.

(Pushing go now but there's more I will try to add)

Doh! Forgot his deathbed lectures on 'The Computer and the Brain'! This was the first time anyone had compared computers to human brains in a systematic manner, and made the point that while computers were serial machines, the brain was massively parallel. The lectures built a bridge between computer science and cognitive neuroscience for the first time--some would say that's been a pretty useful link!