My parents and I stayed at Novotel La Defense in March 2010 (4 nights). Finding a hotel with tripe rooms is a challenge in Paris, if you want a good location without paying a fortune. We are not at all cheap travelers, but a suite at George V is just out of our price range. Booking an old Best Western where you can hear the mice at night was also not an option.
The room was ok, just what one would expect from a Novotel - clean and simple, with a very comfortable pull out sofa. We got a room with a view to the Seine, but the windows didn't open, so we could have spared the 60 EUR spent on the upgrade. We forgot that we had breakfast included, so I cannot comment on the restaurant. Instead, we had coffee and croissants from Starbucks on the steps under the Grande Arche de la Defense every morning and we loved it.
The subway is literally steps away and it is located on line 1, the one that takes you pretty much everywhere. We preferred to get off and walk for the remainder of the distance instead on changing metros, but that's just us - we like to walk.
All in all... I wouldn't go there on my honeymoon, but it is great for families and for people who need comfort and location for a decent (albeit not very low) rate.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC