I have been to many of these cities. Whereas i have lived in London for 3 years, and sadly at 1,5 million my own birthplace is not in the list, i would tend to think that of the ones in the poll Budapest has made the biggest impression on me.
I was only there for a few days though, when i was 14. I still recall how dark and gloomy everything appeared to be, and not less so the extremely impressive gothic Parliament house.
That said, if the vote was on where one could actually live, i would have voted for London (no, i would not want to live in Athens, it is probably the ugliest city in Greece).