I like the 4th, because it includes the Marais, a really interesting area with narrow streets, old buildings, and Place des Vosges, a nice <em>place</em> ("square") for a three-year-old.

We've stayed at the Hotel de Nice a half-dozen times, but it's not for everyone, because it is on a busy street. The location for buses and metro, however, is very good, and it's a two-block walk to the river and the bridge to Ile St-Louis, another nice strolling area.

ssander