San Francisco and New York are two cities definitly worth the trip. I have a personal preference for S.F as a tourist, maybe because I was younger when I visited it and was really impressed by the Golden Gate wich is a masterpiece. You'll find a strong soul in both cities.

Of course I was speaking of the average US city and it's suburbs and malls. I had in mind Los Angeles for example. My grand-mother lives in a very beautiful place in Orange County, but when I "visited" L.A there was nothing at all worth it.

U.S are worth the trip for the sole natural landscapes and national parks. I visited a lot of these and it was more than impressing. Wherever you go, you are overwhelmed by space, the diversity, the endless cornfields, the infinite horizon, and a sense of liberty that is unmatched anywhere else I went. It's even better than in the movies.

Regarding the beauty of New York compared to other cities, you'll have to appreciate it by yourself, a travel to Europe is definitly worth the trip, Italy and France might be your best options. One thing for sure that you'll find is that these cities are really different.