Hey, i'm trying to decide myself.
I'd actually really like to go to Spain and am thinking either Madrid or Barcelona.
Another option for me is Berlin.
As for you Claudius, have you been to any of the above mentioned places, because if not, Paris should be at the top of your list. It's one of the most memorable places i've visited in Europe (i went about 3 years ago). New York has it's charm, but Europe is always a much better experience than USA, IMO.