Hamburg, Germany in a similar way as Amsterdam. Red light district was "interesting" to walk through.
Salzburg
Venice I fully expected to be overrated, but loved it.
My #1 favorite city is Eisenach, Germany. Not necessarily a tourist hotspot, but I've been there 3 times and it probably has more to do with the timing.
All 3 times in the spring right after classes let out. 10 days of sitting on the streets, sipping on the dark beer with one hand and a thuringer sausage in the other. The bun covered just a little of it and a thin layer of mustard running from one end to the other.
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