Florence and Rome are both fantastic cities, especially if you are into history or art. Some of the architecture is truly breathtaking, and the food scene in each is great too, if a little pricy.
Berlin was a revelation - surprisingly cheap, world class museums (and ale!) and great public transport to help get around this surprisingly spread out and uncrowded city.
Budapest was fantastic -spas are brilliant, architecture amazing, food is boss and it’s all dirt cheap. The ruin bars are worth the visit on their own.
NYC is a bit passé now, but I’ve been 4 times and loved it every time. So much to see, so much energy and it’s like a living film set. Love the place.
Prague was great, but not sure how much we’d have liked it if we weren’t being shown round by people who lived there. We didn’t see a single stag do or hen night although there were loads around. The local pubs we were in were fantastically cheap and fantastically good.
other places I’ve visited and enjoyed, but don’t know so well are Cadiz, Lisbon, Vigo, Nice, And Pisa. all thoroughly enjoyable visits and all worth a go.