Mammal Skeletons
The Galarie de Paléontologie et d’Anatomie Comparée in the Jardin de Plants in Paris has a fantastic collection of mammal skeletons, which are even more wonderful when seen amassed as a forrest of skeletons in the museum. I have posted some stereoscopic pictures of the palaeontology gallery previously (see here), but the mammals downstairs are also very impressive.
If you have trouble resolving the images make them smaller and concentrate on a common object in the middle ground. The lower image is not the easiest to assemble by going cross-eyed but it work quite well when you find it. Once you have registered the 3D image try and relax, and the three dimensions will pop out a bit more.