Since it is a short trip, you might find that you get more out of it by seeing "less". You could easily spend five days with Paris as your base and still do some day trips (eg. Versailles). I think if you try to cover too much ground you will find that you spend the majority of your time travelling and don't actually get to see much of France at all. I am partial because I adore Paris, but I can't imagine visiting France without spending a good chunk of time in the City of Light.
What time of year is your trip? Also what types of activities are important to you when you travel (eg. cultural, sightseeing, outdoor activities?)? This type of information is helpful if you are looking for specific advice..