Culturally it has a lot of offer, vibrant scenes for any art or music taste and museums stuffed artifacts stolen from all around the globe[0] that might almost rival the British Museum. Also many musicians and artists have called it their temporary home, from Josephine Baker to David Bowie and his flat mate Iggy Pop[1]. Call it a litmus-test for how open a society is, even if you prefer complaining about the noise and waste the Love Parade (or rather Rave the Planet since last year) produces. On the wider geography, Germany itself is quite diverse, with a 90 minute train ride to Hamburg you will notice a difference in culture and into the south your just-acquired German skill will face challenges from many dialects. The city is also a great starting point to across the borders into the nine neighbouring countries we Germans have fought against and alongside at various points of history. Oh, and we Germans thing we have humour...
Just spent a weekend there: I heard more English spoken in public than German, and even found myself having to backtrack and switch to English (my first language) after instinctively starting conversations in German (my second language). It didn't quite feel like I was still in Germany; only the street signs and some business names brought me back.
A few of the people I met at the tech events I visited have lived in Germany long enough to get citizenship, but haven't applied because they aren't sure they could pass the language exams, and would have to take a lot of effort to get enough practice speaking - they work in English all day, and speak English to all of their friends.
Berlin is a different world from even the larger cities in southern Germany, like Munich or Nuremberg - reachable by high speed train in 3-5 hours.
For Americans, think NYC (Berlin) vs. Dallas (Munich).
It is SO hard to not switch to English when you start talking with someone who doesn't speak fluent German. It's some stupid automatism we Germans have and it took me years to break this habit. Maybe you can do the same and stick to your bad German even if the Germans switch to English? Conversations in two languages sound funny :-)
We have plenty of literature and media in German, and few languages get treated with the same effort by Hollywood distributors like German does.
If you already are a EU citizen, you simply won't bother with German citizenship. It will become an interesting problem for democracy to solve with Luxemburg have some 47% foreigners, not sure how many are EU-citizens [1].
I think I would love Berlin. It is just very different than all the other options presented, so I was curious why it was listed. It is like someone saying they are trying to decide between several types of dark roasted coffee but also having ginger kombucha in the list. Put more succinctly, I did see a common trait between Berlin and the other locations, so I wondered what it was.
TomK32's provided some great insight as a German. For me, the common traits are 1) local language is not explicitly English, 2) has a vibrant social scene, and 3) I know people there already. I'm a techie so cost of living isn't an overriding concern.
