France is just a quick "hop" across the Channel. We've tried the various crossings, ferry (Dover to Calais and Portsmouth to Cherbourg or Caen), flying but tend to go via Eurotunnel for it's speed.
My first ever trip to France was when I went on a French Exchange while at School. My penfriend and her family lived on the outskirts of Paris. There are lots of things to do in Paris, you can visit the sites or just sit in a cafe and enjoy a cup of coffee.
The Eiffel Tower - a 300 metre tower that has since celebrated its 100 year anniversary. I would recommend taking the lift up to the various levels unless you are feeling very energetic - although you do get a good view as you walk up the many steps!
The Louvre - which celebrated its 200th anniversary in 1993 and is one of the largest museums in the world. It was originally built as a palace and became a museum not long after King Louis XVI was executed. It now has a glass pyramid which was finished in 1989 and this is where you enter the museum. There are many exhibits to suit everyones' interests.
The Sacre Coeur and wandering around the Montmartre where you find all the painters.
Versailles - a lovely place to spend the day and take a picnic. Tour the magnificent chateau and walk in the beautiful gardens, the chariot fountain is a great site when the fountain "explodes".
The day trips have been to spend a day shopping, usually at Cite Europe, if you go by Eurotunnel it's right next door. If you are taking children a good place to go is Nausicaa which you will find just down the road from Calais in Boulogne. There is a little beach area there so if it is a nice day you can get the sand between your toes.
One of our favourite places is Normandy. We tend to travel over using the Eurotunnel as it's nice and quick and you don't get sea sick! It's an easy journey down to Normandy, we use the autoroute so have to pay tolls (le peage) but the roads are clear and usually quick and there are facilities to stop en-route and stretch the legs (etc). There are lots of places to visit in Normandy (as with the rest of France) although Normandy is one of the places to go if you are interested in the history of WW2 as there are the landing beaches to visit. We found a nice beach at Julloville which is not far from Avranches. Another nice beach is the one at Carteret.
Of course, if you like Disney there is Disneyland not far from Paris. We've been there twice so far and stayed in the Sequoia Lodge - more on our visits can be seen by clicking on the link on the left.