I thought I'd do a write-up of some visits I did in Paris - I've been many times, but in recent years it has always been as something of a guide myself, so I visited the same major sites each and every time. This trip was all about going places I'd wanted to see and hadn't yet had the chance.
New To Me:
Musée des Arts Forains: This is a private museum of fair and amusement park antiques, including riding carousels (the last one is amazing; that's all I'll say!), playing fair games, and more. It's a bit like arriving in Wonderland. You must reserve a visit in advance online as they are only done by guided tour. These tours are primarily in French, though there are English tours in the summer, and while I was on a French tour, many guests were not French and the guide translated a good portion of his tour.
Museum of the History of Immigration: This museum is what it sounds like, in the Palais de la Porte Dorée, an interesting Art Deco building that also houses an aquarium. The permanent exhibit is fascinating if you understand French. If you don't, the temporary exhibit, Paris-Londres, might be worth a visit anyhow. It covers musical migrations and immigration in Paris and London from the 1960s to 1980s. Lots of things to listen to, fun music memorabilia, and is in French and English.
Quai Branly Museum: Focused on cultures around the world, I recommend a visit here at the bare minimum for the experience of arriving. You walk through the crowds near the Eiffel Tower into such a peaceful garden (although you're likely to see plenty of student groups during the school year). Don't tell too many people, but this could be an ideal lunch spot. I ate my formule from the boulangerie under an incredible rose arbor. The museum can feel overwhelming when you don't know much about what you're looking at, so I found the audioguide helpful. My personal favorite was learning about camel palanquins.
Black Paris tour: I also really enjoyed this tour, from blackparistour.com, which provides some basic orientation to Paris followed by an in-depth examination of the experiences that African-Americans had coming to France and Paris, as well as the role played in French history by a variety of intriguing black individuals, including a good bit of info about the Dumas family. It is a long day with about an hour of orientation in a cafe, but I thought it was so interesting and important to see the city through a new lens.
Atelier des Lumières: Seemed like the thing to do - at first I thought it would be underwhelming, but I loved it by the end!
Fondation Louis Vuitton: honestly, I was underwhelmed by the permanent collection. They do have a Yayoi Kusama Infinity Room though!
Major sites, temporary exhibits:
Musée d'Orsay: Obviously a classic, but I actually only went to see the Modèle Noir exhibit. I found it to be fascinating and well done, with a nice selection of books and literature at the end (particularly if you are a French speaker).
Musée Marmottan Monet: Another classic I visited for its special exhibit on how French painters interpreted "the Orient." The exhibit design was just gorgeous, and it was an interesting subject. Could be paired well with a reading of Fatema Mernissi, particularly something like Scheherazade Goes West. Also, even though people will advise you that you don't really need to buy a ticket in advance, I say do it, then go at opening. It's not a busy museum, but if you go straight in, you might also get the chance I did to spend several minutes totally alone in their Monet permanent collection, just a wonderful experience!
Also, if you are at the Marmottan and in search of a quick breakfast or lunch / takeaway, I recommend Yamazaki, a Japanese-French bakery. You get French classics with a Japanese twist, and vice versa.