We would love to go on a day trip from Paris. Any suggestions? We will be in Paris the first week of April.

There are several threads on this one, if you look back, but the top three recommendations, I'd say are:

Reims and the Champagne region

Chantilly/Senlis

Chartres

That is assuming you have already been to Versailles.

Couple more: Fontainebleau, Blois, or an all day bus tour to Loire Valley (you visit 3 chateaus)

If you're an art lover, don't miss Auvers-Sur-Oise (where Van Gogh spent his last two months) and Giverny (the home of Monet). The SNCF has some package deals with admissions tickets and train tickets both included. See these at http://www.transilien.com/FR/TouSom.htm . (I think Giverny is a little harder to access by train. We went there by car with friends).

any suggestions for a fine dining experience? thank you