I loved both Vienna and Budapest more than Prague, even though Prague has some gorgeous architecture, etc. But it's cynical and over-run with tourists and the people are not particularly friendly.

The Viennese, OTOH, are gracious and their desserts are divine. The Hungarians are less likely to speak English than the Austrians (though why should they have to, it's not their language) but they still go out of their way to try to help you if you get lost, using sign language. They are also lively and friendly. If I were young and wanted to party, I'd go to Budapest. As an older person, Vienna's arts scene is more to my taste.

If I go back to Europe, I will definitely go back to these two cities, and also visit some of the others you named, including Rome, which I have never been to and would like to see at some point. I did go to Athens because it's the "cradle of Western civilization" but as you point out there are issues there.

But thanks for the candid reviews of Malta, Lisbon, etc.