in my opinion, Berlin is one of the most beautiful cities in Europe... I have been there a couple of times and all I can say is, it is absolutely beautiful! You got so many great spots, urban culture, friendly people, amazing night life (there is always some cool nightlife going on in Berlin every single day). Another city which would be really cool to have a meeting is Lisbon, Portugal. The weather there should be always cool. Munich isn't as cool as Berlin imo, the people in Berlin are more open-minded from what I've experienced.