I think the worst exhibit would be the Monkey Firing Range. Annoy the monkeys and see how accurate their aim is.
Technically, those wouldn't be too bad. I think you might be able to get away with the tiger one if its a tiger cub. Even though they can be dangerous when they feel threatened, rhinos are gentle, non-aggressive animals. Still, I wouldn't recommend riding them. Sharks rarely attack humans. Most attacks occur due to misidentifying swimmers. As long as they are adequately fed and you use small species, there wouldn't be any problem. Fear about sharks are brought about by ignorance and Hollywood.
Something like this: http://www.zoochat.com/25/exhibit-would-you-least-want-named-282553/#post580054 ?
I know. Read the name carefully, it says Sleep with Sharks. Not only is swimming with a shark potentially dangerous depending on species, how hungry it is, how agressive it is, and and what you do (size doesn't necessarily matter- look at the Whale Shark) but sleeping with them would mean certain death unless you were part Fiji Mermaid() Almost any zoo that would allow rhino riding, shark sleeping, and tiger petting wouldn't get too great reviews. As you said, a cub might not be too dangerous but I'm talking a full grown, male Amur Tiger. While rhinos can be gentle giant I think it's safe to say that they'd get real angry real fast if you tried to ride it. ~Thylo
What's really crazy is that there's a group of people who make it a past-time by jumping into water filled with piranha.
Not that dangerous unless you have any kind of scrap meat on you. Of course it you get them into a frenzy you may want to watch out. ~Thylo
Stoner Safari- Go in with big cats, elephants and many other dangerous animals while completely baked.