What are good neighborhoods (arrondissments) to stay at in Paris?

I plan to stay a few days in Paris and I’m searching for a hotel right now… Which neighborhood (arrondissment) would you recommend? I need it to be safe at night and in or near the center of the city? Thank you.

Anyone know what neighborhoods in Paris are the nicest to raise a family?

My husband and I are looking to relocate to Paris, or the outskirts of Paris, and I am unfamiliar of what neighborhoods are the best for raising a family, and a safe, hip enviroment. We have a 1 year old little girl and I want to provide her with the best neighborhood possible, so could [...]