Specific species in zoos tend to be much of my reasons for visit cities and even countries. I visited Berlin for trumpet manucode, Duisburg for river dolphin, Loro Park for killer whales, Prague for Lear's macaw, and Benelux for Bulwer's pheasant, Spix's macaws and harbour porpoises. My biggest dreams (unreachable for now) are Pekin for the Chinese monal and the three species of snub-nosed monkey, and Japan for the many fabulous things they keep (dugong, finless porpoise, Commerson's dolphin, rough-toothed dolphin, crested argus, etc). Of course that doesn't mean that I don't enjoy their many other species.