If you are visiting Paris and you have never been before, a visit to le Louvre is probably on your list. And it should be. You should go at least once. I went when I first visited Paris at the age of twelve and again when I was living in Bordeaux. My then-boyfriend-now-husband was visiting and had never been to Paris and his mom always tells a story about the one time she went to Paris, went to visit le Louvre and the museum was closed. He insisted he had to get her a book from there and that he just wanted to see the Mona Lisa. This was fine with me since I had already been before. After standing in line, waiting, and taking a non-flash picture of Leonardo's piece, my husband said, "It was much smaller than I imagined." [Insert that's what she said joke here.]
The museum I enjoyed much more and that I suggest you go if want to see an art museum in Paris is the Musée d'Orsay which holds mainly French art and is best known for its collection of impressionist and post-impressionist pieces (which might be my favorite periods.) What is even cooler about this museum is that it is housed in an old railway station making an impressive backdrop for the artwork there.
I figured I could share some picture from our trip to the museum in 2007. Excuse the fact that most of the pictures are blurry - obviously you shouldn't use the flash in a museum. (Also, excuse the fact that my then-boyfriend-now-husband looks miserable. He was so sick the entire time in Paris. But I insisted since he will probably not get back to Paris for awhile, he could not sleep all day.)
It is so funny to me how young we look in these pictures. It only seems like a year or two ago but I just realized that I left France almost three and a half years ago. Wow!
Have you every been to Paris? What were your favorite museums? If you haven't been to Paris, what museums do you want to visit if you go?