need location for a 3 week stay in Normandy

Bayeux is a great location, especially if you are interested in the D-Day beaches and associated sites . We've only stayed a shorter time in hotels so I can suggest rentals but it's a great little city.

Another vote for Bayeux. It’s a charming little town, and big enough to gave the basics: several restaurants, grocery stores, etc. The other villages near the D-Day sights are much smaller. Be aware that traveling off season could mean some places are closed in between seasons. We experienced this in November, when about half the restaurants were closed. Even the ones directly across from Utah Beach museum. In one village we couldn’t find a single restaurant open and had to make our way back to Bayeux.

I hope you will have a car for your tour. The area does not have good public transportation access for dday sights.

Normandy isn't particularly small. I wouldn't choose to stay in one place for three weeks and drive back and forth almost every day. It's about a 4-hour drive from one end to the other. Bayeux has much to recommend it, but it's close to a 2-hour drive from Rouen, which is by no means the farthest point in Normandy.

I'm curious what your interests might be in Normandy. That would help determine where you might stay. It appears several comments were made under the assumption you would be interested in visiting various D-Day sights, especially those associated with American landings, but it would be good to read about what kinds of things you plan to visit during your stay.

We want to explore the area at a leisurely pace. We plan to take in the beaches, Rouen, etc. before our extended stay. May take a short trip to Mont St. Michel and/or St. Malo, but otherwise like to spend some time living in an area and really get to know it. So I guess we are looking for someplace that is charming and/interesting, is very walkable and would just be a nice place to hang out. I know Normandy is a big area - don't expect to see it all and wouldn't be driving off somewhere every day. Just want a nice taste of the area.

I second the suggestion of staying in Bayeux for an extended period of time in order to get a feel for a smaller French town. They have interesting things to see there; a nice public market; and some very good restaurants. It is a pretty walkable city, as it does not have steep hills. Peter

I don't mean to harangue you, but all the places you've mentioned wanting to see (Rouen, Saint-Malo and Mont-Saint-Michel) are quite some distance from Bayeux and would not be places I'd day trip to from that town without a car. Saint-Malo and Mont-Saint-Michel are quite close together, and there are many other interesting towns over in that area (Dinard, Dinan, Fougeres, Vitre), so I'd want to spend some time there and make convenient day trips to the surrounding attractions.

Before coming to a final decision, I recommend researching public transportation between your proposed base and the places you want to go. Bayeux is a very pleasant place, but I'd run out of things to see there after two or three days. Caen's an easy day trip by train, but it was nearly totally flattened during the war and has only a few tourist sights I'm aware of. Despite its limitations from the tourist perspective, I chose to split my time between Bayeux and Caen since Caen has good bus and train links to places I wanted to see; otherwise I'd have been a frequently traveler on the Bayeux-Caen train, and that just didn't make sense for me.