Crowded and dirty
Paris is a city too crowded and dirty. It definitely is not the best place to visit (if you want a stress free trip). If it is the trip of your life, go for it, but if you are looking for a place where things work properly and people are respectful and kind, Paris is not the place. I met very few people willing to help with information there (yes, there are some kindhearted individuals there, but I think most of them are foreigners, lol, sorry!).
Insider Tip:You better learn French and start studying the subway map before landing in Paris and don't forget the pickpockets.