Replying to Where should I go?

I'm currently in the process of taking a leave of absence from this current semester due to scheduling issues & other reasons. & with that said, I am looking to "move" to a major city for a 1-2 months but I can't really decide what would be a good fit for me at the moment.

My current top 6 in no particular order:
- London
- Zurich
- Vancouver
- Split
- Lisbon
- Warsaw

I was thinking of doing two weeks in ldn, two in Zurich, then two in Warsaw.

But I honestly don't know. I'm not too particular with requirements besides the city being beautiful. Looking for a solid art scene & good nightlife. I would like to stay clear of the US (I live by NYC). Taking recommendations; where have you been & how did you like it?