It's always good to check out what's happening in Fondation Cartier. They have lots of really good exhibitions of modern art, and the gallery itself is very beautiful. Perfect for seeing works you already know as well as discovering new artists and inspirations.
Among numerous art galleries in Paris, this one is seriously worth visiting. Very inspiring place with lots of great exhibitions. Yes, too much coolness and beauty in Marais can make you dizzy, but we like it, don't we?