Three Nights in Paris-What area should we stay in?

The Marais is very central, very "Parisian", and within an easy walk to many of the main sights.

I concur with the suggestion of Le Marais but it can be costly. I have found that hotels in the Latin Quarter are slightly less and it can be just or even more efficient than Le Marais depending on the places you wish to visit. Of course, you can visit Paris efficiently from just about anywhere in the city, but perhaps most efficiently from a place in the single digit arrondissements.

Actually anyplace in the single digit arrondisments within a short walk to the metro would work. I stayed in the Marais and loved it, but I wouldn't mind any place in central Paris near a metro. Most people suggest something in the 4th, 5th, 6th and as close to the river as possible. That would put many of the 'main' sights within walking distance or a very short metro ride.

If you feel comfortable with numerous other tourists, you'll enjoy the 4th (Marais), 5th, (Latin Quarter), or the 6th (St Germain des Prés). If you prefer a more something less touristy, I might recommend the neighborhoods around Montparnasse, République, or maybe around the Bastille.

When selecting hotels, stars mean little to nothing. Offering a budget window in euros is far more useful in helping you find appropriate accommodations.

i cannot recommend Rue Cler highly enough. Literally 10 minutes walk to the Eiffel tower, the Rodin museum, Napoleons tomb and 20 to the Louvre and other great museums. The area is quite with a wonderful street market scene right out your door. We saw it on a RS episode and have stayed there twice since then - and planning to go back. If you have scene the show "Somebody Feed Phill", one of his favorite restaurants is a 5 minute walk. It took me 15 because I just loved walking in the area. We stayed in an Airbnb which was great but I do know there are a couple of hotels right on the street.

Wow, 20 minutes from Rue Cler to the Louvre on foot. Was that walking or jogging?

LOL .. no from Rue Cler to Louvre is not that fast.. unless you are a speed walker..

I recommend the 4th ( Marais) 5th (Latin Quarter) or 6th( St Germain) for such a short stay.. three nights is only 2 full days.. so staying in a less central area is not really needed.. Stay closer to river than farther from river in any of those areas.

What is your actual budget per night.. in euros.. the star system is not really that helpful..

We liked the Hotel Le Regent in the 6th.. however you must book their luxe rooms.. their standards are tiny.. the location is perfect.. the staff super helpful, and the bathrooms are a decent size

I agree with others, the Marais, Latin Quarter or St Germain area are ideal.
Notre Dame is the center and heart of Paris, so as close to Notre Dame as possible is good. Get a good map of Paris (i like Michelin laminated maps) and see where everything is, this will help you choose where to stay.

We enjoyed our stay in the Latin Quarter:

https://www.hotel-grandes-ecoles.com/index-en.html

The setting was beautiful - quiet yet convenient to everything. For dinner, we would often buy takeaway food and a bottle of wine and eat in the garden.

On our first morning, we met a woman who stays at this hotel twice a year, and has been doing so for the past seven years. A couple of days later, we talked to another couple who had been coming to the Hotel des Grandes Ecoles for 20 years. Toward the end of our stay, we met a woman from Canada who had been coming to the hotel every year for the past 40! She said: I have travelled all over the world, and this hotel is my favorite spot.

I’ve aleays heard good things about the Hotel des Grand Ecoles - however if visiting in summer I wouldn’t stay there as they do not have ac ( or have they put it in now ?)

I never "got" Paris until we stayed in the 10th Arr. by the Canal St. Martin. It's not for everybody, but I just loved it. We will be staying at the Le Citizen again this fall.

https://lecitizenhotel.com/en/

I have been to Paris twice and each time I stay at the Hotel LeVeque on Rue Cler. Great value,speak english, elevator, walking distance to many eateries, pedestrian street, two blocks from subway. Get a room facing the back because at very early in the morning, the garbage trucks and the delivery trucks create a lot of noise.