Paris has many unusual shops, but one of the most unusual has to be Deyrolle, a 170-year old establishment on rue du Bac, not far from the Musee d'Orsay on the Left Bank.
To describe it as a taxidermy shop hardly does it justice. The ground floor looks like a fairly ordinary small home and garden shop (apart from a couple of stuffed gazelles standing on their hind legs and dressed to look like humans). But walking up the stairs is like passing through a time warp. The second story (which in France is considered the first) appears to have changed little since the store moved to its current location in 1881. It's dusty, chaotic, and crammed with stuffed animals of all shapes, sizes, and poses, as well as ancient wooden cases full of insects, shells, botanical prints and a variety of curiosities.
As the pictures here suggest, it's really a museum masquerading as a store.
UPDATE: June 2011 - Deyrolle appears in the new Woody Allen film, "Midnight in Paris." It's described in this article in The Washington Post.