I love most of the places listed here, especially the cities (they are the places I have mainly visited).
NYC, Amsterdam, Barcelona, Stockholm, Copenhagen, London, Budapest, Venice, Rome, Naples, Dubrovnik, Paris - all amazing. It's interesting that people say NY doesn't live up to the movies as for me it absolutely does. I suppose it depends which films you are thinking of but for me the skyline, the manhole covers with steam, the people, the snippets of conversation you overhear, the diners, the chaos but also the quieter bits - all totally lived up to my expectations. I'm also interested that so many people comment on places being dirty - I don't think I've ever particularly noticed a place being dirty or clean - not entire cities.
I've enjoyed something about everywhere I've ever been, but places I haven't loved have been:
Belfast - the city centre just seemed quite rundown, but I did enjoy the trip to Giant's Causeway, the indoor market, the bus tour with commentary (DS loved the old school humour) and the C S Lewis cafe. So quite a lot really.
Sorrento - A bit bland and just not as nice as other places on the coast, or Naples.
Skye - Beautiful of course but I felt it a bit limited in terms of eating out/cafes. Yes, I'm more of a city person so this is on me.
Seahouses - stupidly went camping with two dogs and 5 month old ds at the end of May. Was freezing, ds wouldn't sleep properly (well, he didn't at home, so why would he in a tent?) and I just found it bleak and depressing, probably because I was exhausted. The final straw was trying to get a morning coffee in a local coffee and only instant was available - it was 18 years ago. It put me off the whole area, probably unfairly.
Malia - cheap last minute holiday with now ex dh. It is what it is but we spent most of our time in Aghios Nikolaos and wishing we had brought a driving licence to hire a car.
All of these places had something to offer though and the ones I didn't like I probably should have known not to go to.