Vienna waits for you.
Of the places on the list, the only one I have been to is Berlin, but I loved it. The history is all so fascinating and recent enough that it is still really fresh and you can really see it all. It is also reasonably affordable. We went on a really great walking tour when we were there. Highly recommended. Just stay away from the zoo*.
*I find zoos to be depressing in general, but I remember this one being especially bad.
I haven’t been to all of those, but Budapest is my favorite city in the world. It’s cheap, the people are incredibly friendly, and it’s a great city.