Hotel at Charles de Gaulle

I've stayed at the Sheraton which is inside Terminsl 2 at CDG, right above the TGV station. No shuttle needed, just walk to your gate.

marriott.com/hotels/travel/parsi-sheraton-paris-airport-hotel-and-conference-centre/

Ibis inside CDG -- walk to the intra-airport free shuttle train. Not fancy, but serviceable for a morning flight.

We’ve stayed at the Hilton and wouldn’t do it again. You can walk to the tram for the airport, or take their free shuttle. What I didn’t like was that they charge extra for wifi. $25/day. In this day and age? Really? The shower in our room had no hot water, and it took a long time for them to figure out another room to move us to. It made me wonder if the bathroom had been cleaned, or with just cold water.
At the end of our trip we opted for the Sheraton. It’s in a terminal, 2, I think, so you just walk to where you need to be. A little more expensive, but much nicer, and the breakfast was included.
There are several other hotels near the Hilton. Just google or look on booking.com.

Elly, there are several hotels right AT the airport; we stayed at the IBIS. Literally maybe 100 ft walk to the free airport tram that goes to all terminals.. There was also an IBIS Styles next door. Be careful because some hotels refer to themselves as 'xxxx hotel CDG' but they are not AT the airport so you have to wait / hassle with a shuttle van. Enjoy your trip!

I had a good experience at the Citizen M hotel - walking distance from Terminal 3. This is how they describe it: “citizenM Paris Charles de Gaulle is just a short (covered) walk from Terminal 3. Or as we say – so close, we don't need a shuttle bus!”

I also stayed at the Sheraton that is inside Terminal 2 and had a good experience. Again, no need for a shuttle.

Bob makes a very good point. For example, you have to read carefully to catch that one Ibis is at the airport, a few steps from the T3 tram stop. The other is at a group of hotels which share shuttles that require much more time to get there. Many years ago, that group was the only option for staying really close to the airport. No longer.
My personal preference is to be as close as possible. Even with staying at the Sheraton, the preliminaries at CDG take quite a bit of time. If you are traveling on a U,S. Passport and leaving the Schengen zone, there is an additional check besides the usual ones, for example. It is a very busy airport, and you can anticipate long lines.

Here is a list of all the hotels at CDG with easy access to terminals via the free train CDGVAL.

https://easycdg.com/hotels-cdg-airport-de-gaulle/

We stayed at the Citizen M/CDG in 2019, and like Renee, we found it perfectly fine for the last night in Paris before an early flight.

With that said, the very comfortable beds are up against the walls and the window - so if there are two of you, someone will not have direct access to the room. The lights and tv are controlled by a tablet, and if you can't find the tablet in the middle of the night, a trip to the bathroom can be an adventure.

As an elderly couple who have flown in and out of Paris often over the last 10 years, we are all too familiar with juggling luggage on to and off of navettes or shuttle buses. That, plus finding the correct bus to the hotel of your choice is bothersome . Now there are more choices right at CDG which requite no navettes. We like the newer Holiday Inn Express near the terminal 1 end of the tram which runs from one end of CDG to the other. It's a short walk, about a half block, but the price is right and it lives up to the Holiday Inn standards. Google it for more info.

We stayed at the Novotel* at CDG in June 2019 and it was a 2-minute walk to the check-in area in the airport. It couldn’t have been more convenient. The previous day had been the summer solstice and the hotel participated in the country-wide music festival so it didn’t feel as if we were stranded in the middle of nowhere. There was a DJ and great music in the outdoor restaurant which made an otherwise anonymous hotel restaurant quite festive. The food was reasonable and they had a good and reasonably priced wine list. The room was spacious enough for 1 night and more importantly, the bed was comfortable and the room sound proofed. I’d stay there again in a heartbeat.

*Edited 07 JUN 2021 to correct the name of the hotel chain.

To echo Laura B and Bob and Roslyn, we stayed at the ibis AT CDG. Not the ibis styles. Perfectly adequate. Clean with a firm bed. And right at the terminal. Also inexpensive. They will give you a small additional discount if you join their "club". You can start at booking.com and use their map to determine which hotels are actually at the airport. I would then book directly as it seems to save a bit of money.

We stayed one night at the IBIS, outside security but not far from the RER. It was basic, but worked just fine.