As Daffy34 said these are the best I've seen out there.  But be sure to look up textures for them.  That makes all the difference in the world for a model.

Where do you find better textures for the old Chimp? I have the Silverleaf monkey and it at least is lovely and their gorilla has had a good run and have a few good textures for it and renders well. But have not found anything for the chimp since I bought it in my previous life!