Paris 2013 - Musee d'Orsay
If you only have time to visit one museum in Paris, make it the Musee d'Orsay. Housed in an old train station, the museum itself is not huge like The Louvre, but is impressive with its large vaulted central gallery which span the whole length of the museum. The museum features mainly French art, but its crown jewel is no doubt the Impressionist and Post-Impressionist collection - the largest in the World, featuring paintings by Monet, Manet, Degas, Renoir, Cézanne, Seurat, Sisley, Gauguin and Van Gogh. Unfortunately this is the few museums in Europe we visited where photography is not allowed, and they are serious about it.
The impressive vaulted main gallery.
What I liked about the museum is the way the collections are organized. It is very easy to work your way around the collections, and the large central gallery provide much needed relieve from the crowds which can sometimes get too much. Besides the Impressionist paintings, the museum also feature many exquisite French sculptures from the 19th century. Many of these are housed in the central gallery which has sufficient space for the objects to "breathe", and this remain one of the favourite art spaces I have ever visited.