Yes, the museums of Paris collectively hold a good portion of the treasurers of Western Civilization, and yes, each is so distinct from all the others that each must be experienced on its own terms.
This is why I smile as I think of me running through the Musee d'Orsay moments before its closing time and happening upon a room full of the paintings of Vincent van Gogh just by chance. Between his landscapes, his portraits, his self-portrait and his painting of a starry night sky, even I would acknowledge that he deserved a little more time. The always misunderestimated Mr. van Gogh.