I REALLY like .CITY but I do not personally like the high renewals for premiums, even if I understand that business model. My own best ones are probably; Bet .city, Temple .city and Phuket .city.
Ps. Newyork .city seems to be reserved by the registry. That would be a killer domain! Maybe a million-dollar-one in ten years?!
I like the extension and as in any new gtld the extension has to match the keyword. From the three you listed, I like NewYork.City and Manchester.city but not LasVegas.City.
Personally I only have one, SaltLake .City