I disagree with passion. The vision of Larry Page and Sergey Brin is responsible for Google's success. Jeff Dean, Sanjay Ghemawat executed Page and Brin's ideas, but they were not the key decision makers. Did Dean and Ghemawat decide to buy and then build Android? Did they decide to build Google Maps? Did they decide to buy YouTube?. The answer is no. Page and Brin would have hired other smart people if Dean and Ghemawat weren't available or had they left Google.
I agree, as I was not talking about the overall success of Google, just the success of Google's secret sauce (their backend infrastructure) that enabled it to sell ads and deliver search results with a high level of quality. If you read some of the books about early Google, they (Jeff, Sanjay et al) were really, really struggling to do stuff like index the web without the crawler collapsing mid-way. That's how MapReduce became to be developed.
Yes, Danger/HipTop, YouTube, and Keyhole are arguably the three smartest acquisitions that Google made.
