The Brookings Metropolitan Policy Program recently took a look at the top 200 cities around the world in terms of aggregate economic output. That allows me to borrow their data and bring you the ten highest-productivity cities among the top 20:
Note that these are metropolitan areas. The municipalities of Hartford and Bridgeport are not rich, but the large swathes of suburban Connecticut that they serve as hubs for are. I don't have a huge policy point to make about this, but I will note that people sometimes wonder why the high-tech economy doesn't create broadly shared prosperity. Part of the answer has to be that the specific places in the United States where high-tech industry is concentrated are, in fact, among the most propserous places in the world. It's just that relatively few people live in them.