Pros
Great salary: in operations or restaurants, you will start at $12.05 for the first month, then get raised to $13.69, and you can expect up to almost $20 after a few years. As soon as you have a steady position, you'll be guaranteed to work 40 hours per week from the end on June to the end of August. Coworkers used to be really fun and interesting people, but they have been hiring a different type of people recently. There's a variety of positions to suite all tastes: if you don't like being outside when it's hot, be a cashier; if you don't like staying always in the same place, work for maintenance; if you want to be outside but don't want to walk all day, work as a ride operator.
Cons
Management is horrible: most managers, even at quite high levels used to be seasonal employees, and just couldn't find another job when they finished their studies. They have no formal training in management, and it shows. A typical work schedule is 12.5 hours per day, 7 days every two weeks, so you get 7 days off, including one long weekend every two weeks, but you end up being too tired to do anything on your off days. Expect to be on call for most of your first summer though.