I love tigers and lions, but not necessarily for big cat watching in the zoo. Many times their napping, taking a snooze, hiding away from people in a cave, and not that exciting. I think the animal specie that offers spectators the most enjoyment are many kinds of monkeys and apes. I remember on my zoo trips observing chimpanzees, Koala bears, and orangutans, climbing trees, hanging onto branches, swinging around on ropes, and engaging spectators. Of course, it depends on the amount of square feet reserved for particular species. San Diego Zoo, California, has outstanding exhibits for their monkeys and apes.