When you go to Paris, or London, or New York, you immediately know you're in a 'world class' city. It just feels that way. Of all the West coast cities, San Francisco comes close but not quite. Kind of like Chicago with a 3rd dimension.

I visited a couple of years ago, and was struck by how far downhill the downtown area had gone, at least in comparison to my previous visit say 10 years earlier - aforementioned street people the main detraction. Cured any ideas I had about moving there (would never have considered the endless suburbia of Silicon Valley, gives me the willies just thinking about it.)