I think that the orangutan, gorilla and chimpanzee exhibits at Berlin Zoo are all pretty good. Nothing world-class, but more than adequate for those species. The great ape enclosure that appears to be small and a bit old-fashioned would be the exhibit for bonobos on the other side of the Primate House.
I also think that the Apes outdoor areas are both very good for the species and aesthetically pleasing. Especially the Gorilla's. They need to think about the Monkey area, though.
