1. Roller coasters with dead ends and explosive finishes (obviously). For added effect, line up a bunch of people where the roller coaster would fly off and land.
2. Roller coasters that get stuck...forever (who needs mechanics?).
3. Roller coasters that are unnecessarily long and overly nauseating (in the spirit of Mr. Bones' Wild Ride). You can also chain them together so that one ride's exit leads to another ride's entrance, and guests are forced to ride all of them.
4. Rides where guests fall directly into water upon exiting -- complimentary 'refreshments' with each ride!
5. Giant path mazes...with no exit! Make sure to remove all handimen/security guards -- gotta make sure the paths are soaked in vomit and litter!
6. 'Paradise': leave a single guest in a small, isolated area, complete with food stands, restrooms, scenery, etc. Every vacation come with a price, though -- everything is at maximum price.
7. Raise a tile to maximum height and drop a guest on top. Great view of the park!
8. Dig a tile to minimum height and drop a guest inside. Not-so-great view of the park!
9. Block the park's exit off to prevent anyone from leaving. The fun lasts forever~
10. Overpopulation -- place everyone on a single tile. Surround with flowers.