It's Mickey vs. Shamu. (Amusement Parks: Survey).(Buyers Guide)

Sit back and hold on tight. Here are CR's first Ratings of America's theme parks, plus how to save hundreds of dollars and avoid mobs of Mouseketeers.

Last year, 320 million visitors rolled and twisted, strolled and sat through more than 3 billion rides and attractions at America's 450 fixed-site amusement parks. Here's another impressive number: $10 billion. That's how much those visitors spent on admission, food, and souvenirs.

For many, the expense was a surprise: In our own survey of nearly 2,500 parkgoers, the trip cost more than expected-- sometimes a lot more--almost 40 percent of the time.

We supplemented our survey with research from staffers who visited theme parks. We asked roller-coaster fans to name their favorites (see page 30) and interviewed experts about risks associated with ever-faster rides (see page 31).

As a result, we can tell you which of 14 of the nation's most-visited theme parks are the biggest crowd pleasers and best values. We'll reveal how to save hundreds of dollars on your trip. And we'll offer tips on how to avoid crowds, long lines, and overpriced concessions. Among our findings:

* Sea World and Epcot, both in the Orlando, Fla., area, earned top scores for value. More than 40 percent of the visitors to those parks said they were well worth the money. By contrast, less than 30 percent of visitors to Disney's California Adventure, in Anaheim; Knott's Berry Farm, in Buena Park, Calif.; and Universal Studios Hollywood and Florida said they got great value.

* Overall, park-goers were highly satisfied. Yet 24 percent had three or more complaints, especially about overcrowding and long lines. The worst offenders: Disneyland, in Anaheim, Calif., and Cedar Point, in Sandusky, Ohio. Almost half of the visitors to Cedar Point said they had to wait at least an hour in at least one line.