The City of Sunnyvale released its 2007 Resident Satisfaction Survey, which highlighted that 93% of respondents felt that Sunnyvale was a good or excellent place to live. 84% thought the same of their neighborhood. This chart was taken directly from the PDF document which Sunnyvale provides from the National Research Center.
I thought it was interesting that those folks in the 9% difference didn't like where they were living all that much, but still liked Sunnyvale as a whole. (Usually people who don't like one prefer their neighborhoods over city itself.)
That satisfaction rating puts Sunnyvale in the 81st percentile nationwide. Not bad. People didn't think highly of the city as a place to retire (26th percentile) or --- shockingly --- as a place with access to "affordable quality housing" (24th percentile). It is the "Heart of Silicon Valley" after all.
But where Sunnyvale excelled in the survey was in "openness and acceptance towards people of diverse backgrounds" (95th percentile), "quality of police services" (93rd percentile), and value for tax money spent (94th percentile).