Can't really think of many I didn't like
Reykjavik- not a lot to do but nice for a day,
Athens- hot and dirty, but again, good fir a day or so
Singapore- some nice bits eg raffles, parks, but found it a bit dull and so depressing to see a polar bear in the zoo
Loved
Stockholm - beautiful, gorgeous boat trips if you want a break from the city, great food (but sickeningly expensive)
Saville- hot in autumn, gorgeous old parts, not too expensive
Berlin - large and noisy, but so interesting, history at every turn, and fairly cheap by capital city standards
Krakow - beautiful, historic, cheap, friendly
Edinburgh - lived there for quite a time and loved it, my favourite city. Though visited last year and felt a bit disappointed for the first time - freezing wet, busy, expensive. Shows how changeable things like weather can really influence an opinion.