My sister has had 3 "ornamental" pugs and all have been highly intelligent. The one she has now (Owen) is 3 years old and if you ask him to bring you his blue bone (as opposed to his white one which is identical in every other aspect) he will bring you the correct one 100% of the time. He is also one of the funniest dogs I've ever met.

My Siberian Husky was also extremely smart but very mouthy and high-strung...true to the breed.