Both Prague and Lugano are great. We were in Prague this last January. Met a Hungarian couple at the Christmas market that were on their way to Amsterdam from Budapest and we had a few drinks and socialized with them. Great fun.I had company apartments in Prague and Lugano, Switzerland. The latter was one of the coolest places I've been and totally off the radar screen for most from the US. (Most Americans go to Como and turn around - missing amazing places less than 20-30 minutes away.)
My company had operations in / near Paris, London, Peterborough, Napoli, Turin, Karlsruhe, Basel, Warsaw, and a couple of other places where I spent a fair amount of time. Prior to that I did a couple of stints in Tel Aviv consulting for Israeli banks - great place!
Lugano is gorgeous. Palm trees in Switzerland ? Who'da thunk it. Our favorite thing to do is get some wine, snacks and all day passes for the Swiss ferry boats and ride around the lake all day.
If you haven't done so already, you should ride the "FART" (train) from Locarno to Domadossola. It's a pretty "quaint" train and it takes you through some beautiful scenery and rustic Italian villages before dropping down into the valley where Domodossola lies.
I'm mostly an Alps/mountain kind of person. But if I had to live in a city, it'd be Luzern. The other big Swiss cities don't do much for me, other than perhaps, Zurich.