Favorite museum? Can there possibly be such a thing? For me it would depend on which city I am in. New York City? Paris? Washington DC? St Petersburg? Amsterdam? London? It is impossible to choose a favorite.
I love the big museums, and the small ones, too. In Paris, of course the Louvre or could it be the Picasso Museum or Alexandre Dumas Museum or the Eugene Delecroix museum? I love each one for different reasons.
I love living history museums. Art museums, Natural history museums like the Field museum in Chicago, oh and what about the Smithsonian in Washington DC? Each one is a favorite for different reasons!