First of all, it should have great weather conditions all year round.
Secondly, there should be neither crime nor any violence there. Only good and kind people can reside in such city. Life can be much easier and nicer if everyone is loving and understanding. In the my world people will live in peace and quiet, without any worries and fears.
This world will have excellent roads, cheap stores, many beautiful parks and playgrounds for kids, several entertainment centers and else.
The population of the city will be neither too rich, nor poor. People will live equally well. Older people will be respected and taken care of.
The streets will be clean and safe. There will be no homeless animals in my world.
However, I certainly understand that it’s just my dream, I really hope that at least some of the mentioned qualities will come true in the future...