My favorite animals to see are hyenas. That said, I'm a hoofstock guy more and more the older I get and the more zoos seem to get away from keeping a wide variety. I think it's a tendency a lot of hardcore zoo fans likely come to after awhile. You can see lions, gorillas, elephants, giraffes and bears at just about any medium to large park. On the other hand, You're not likely to see the same species of antelope at all parks. I get excited about seeing sable, wildebeest, kudu, duikers, eland, etc. Unless you frequent the Bronx, it's super tough to find a zoo in the States with a decent variety of Asian hoofstock.