Why do Americans like Europe so much?
Bryan gives some good reasons why America is better for 37-year-olds with young children, namely lots of living space and easy shopping. But I view much of Western Europe as better for the elderly, if only because it requires less driving and they are more likely to live close to their children and perhaps also they receive more respect. Western Europe is probably better for children too, for reasons related to safety and health care.
My alternative view is that Americans rate European life so highly (in part) because the buildings from previous eras are so striking and attractive. If all of the U.S. looked like U.S. postwar construction, the country would still impress more or less as it does. If all of Europe looked like its postwar construction, Americans would be less likely to admire European policies and political institutions. Yes I know about Lille, and contemporary Spanish architecture, but in reality most Americans would think of Europe as some kind of dump.
Tyler is spot on, I'd say. Without the pretty buildings, what would often most strike Americans is the cramped space and a succession of petty inconveniences. One of my friends who lived in Toronto, and is a raging europhile and a liberal, was nonetheless fond of pointing out that, due to a building boom in the 1970s, much of the city reminded her of nothing so much as her childhood in the Soviet Union. Toronto is a lovely, liveable city for most of the reasons that people say they like European cities. But its architecture is mostly pretty dreary, and it rarely captures the heart of American tourists or ex-pats the way that London, Paris, Rome and Amsterdam do.