In 1986, Paris consolidated most of its collections of French art from 1848 to World War I in the most unlikely of spots: a old converted train station.
While the museum does contain earlier, mid-19th century works by the likes of Ingres and Delacroix, without a doubt the Orsay's biggest draw is its massive collection of paintings and sculptures those crowd-pleasing Impressionists.
So many of the works here are so widely reproduced that you might wander through with an eerie feeling of déjà vu.
There are Degas' ballet dancers, his l'Absinthe; Monet's women in a poppy field, the Rouen cathedral painted under five different lighting conditions, a giant Blue Waterlillies; Van Gogh's Restaurant de la Siréne, Starry Night, self-portraits, peasants napping against a haystack, and his Bedroom at Arles.
Then there are artistic icons of surpassing fame: Whistler's Mother; Manet's groundbreaking Dejeuner sur l'Herbe (Picnic on the Grass) and Olympia, which together helped throw off the shackles of artistic conservatism, giving Impressionism room to take root.
Add in a generous helping of Cézanne, Gauguin, Rodin, Toulouse-Lautrec, Pissaro, and Seurat, and you could easily spend a full day exploring this museum.
Budget at least 90 minutes to spend in the Musée d'Orsay—though personally I'd give it about 3 or 4 hours. This is, afetr all, the single greatest collection of Impressionist works in the world.
You can get a "passport" ticket covering admission to both the Musée d'Orsay and the Orangerie for €14 (as opposed to the regular total ticket price of €16.50).
It lasts for four days, but is good for only one admission at each museum.
Admission to the Musée d'Orsay is free—and the museum is intensely crowded—on the first Sunday of every month.
Whistler's Arrangement in Grey and Black No. 1—more popularly known as "Whistler's Mother" or "Portrait of the Artist's Mother" (1871)
Manet's naked Olympia (1863).