Where would be a good place to stay in Paris for easy access to and from CDG?
Any hotel close to Gare du Nord would do nicely, if your only criteria is easy access to and from the airport. By the same token, any hotel close to a metro station would do as well. Do you have a budget in mind? Oh, and see parisbytrain.com for info about getting to and from CDG.
Bonjour! I agree with the comment above. Public transportation opens up alternatives. For example, in lieu of staying close to the airport, I'd suggest staying in the city. Using public transportation, you can access the following hotel (and others on Boulevard St Germain) pretty easily: Hotel Marignan: http://www.hotel-marignan.com/ I love this place, and I am staying here again this summer. This is not a "fancy hotel" -- I don't know whether Rick would recommend it -- it is very basic. But I absolutely LOVED being only six blocks from Ile de la Cite and Notre Dame! It is right near Cluny on the left bank and only a few blocks from the Boulevard St Michel metro stop. Do not expect being catered to or being served a fancy breakfast (when I went last  it was only bread, condiments, and coffee). It is a very European hotel with a cozy hostel feel: You can use the kitchen to fix your own meals, peruse a host of tour books in their library, do laundry. Some bedrooms have a toilet and shower; for others, the facilities are down the hall. The BEST is being able to walk out the door to many sites without using a taxi or metro. I lived in Paris for my junior year abroad. Staying here brought me back home! ...Whatever you decide to do, enjoy! Paris is truly amazing. -Ana