Chuckanut
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
We visited the Musee D’Orsay in May 2015. We went in the evening. It wasn’t so crowded and we got a good look at the paintings plus had a nice evening meal.
The Musee de l’Orangerie was the best. We got there right when it opened. We had it mostly to ourselves for the first hour. Had the murals to ourselves at times. It was lovely.
I skipped the Louvre, and now I’m glad I did. DH had been in the 70s and wasn’t enthusiastic to return, plus remarked about the Mona Lisa being small. We just got a combo ticket for the other two museums as we were more interested in impressionistic paintings.
I found the Louvre to be like hiking trails in national parks. The farther you get away from the few 'must see' pieces, the less crowded and more pleasant the experience becomes. Still, one should not go there expecting to not have to deal with many other people.