While Marriottīs Champs Elysees location is in my opinion overpriced, Renaissance Paris is a great place to stay for business and/or pleasure. La Defense/Grand Arch station(RER line A, Metro 1)is five minutes away from the hotel entrance. RER line A brings you for example to Grand Magazines such as Galeries Lafayette and Printemps (Auber), Chatelet-Les Halles stop is convenient to Louvre, Palais Royal and Centre Pompidou.
Leaving CDG, take RER line B and change in Chatelet-Les Halles for RER line A to La Defense/Grand Arch.
Have fun!