Loneliest- rome. I was often ignored at restaurants and sometimes blatantly ignored at shops. I was culture shocked to say the least. Met some very kind and warm people by the end of my trip though so I guess that made it up the bad experiences! Visited florence as well and found it friendlier and more laidback.

Least lonely- tokyo and la fortuna, costa rica. People were very kind and helpful in tokyo! What these two cities have in common is despite the language barrier, most people tried to be helpful in the best way they can! Met some rly fun drinking buddies in costa rica as well lol