TripAdvisor Inc (NASDAQ: TRIP) users have chosen the best amusement parks in the United States and beyond, and almost all of them are owned by three American companies. Among the top 10 U.S. theme parks chosen for the Travelers' Choice awards, four are owned by The Walt Disney Company (NYSE:DIS), three by SeaWorld Entertainment (NYSE:SEAS), and two by Comcast (NASDAQ:CMCSA) subsidiary NBCUniversal. The only other company whose park made the U.S. list is Cedar Fair Entertainment Company (NYSE:FUN); its Cedar Point Amusement Park in Sandusky, Ohio, ranked eighth.

The fun-park dominance isn't limited to domestic attractions, either. Globally, seven of the top 10 are Disney, Universal, or SeaWorld parks. And if it seems like Orlando is the center of the theme-park universe, that's because it is. Six of the top 10 U.S. amusement parks and five of the worldwide top 10 call Orlando home -- far more than any other city.

The Big 3 have an IRL advantage

With the concentration of theme-park popularity in so few corporate hands, the sector is something of a throwback to pre-Internet days. In contrast to music, television, and even books -- where there are so many relatively new niches and digital distribution channels -- size, brand, and physical location are the prime determinants of theme park success.

That probably won't change any time soon, because of the cost of setting up, maintaining, and upgrading a theme park -- as well as the fact that, unlike recorded music and movies, you have to actually go there to experience what an amusement park has to offer. And the most popular parks look tough to beat.

Discovery Cove. TripAdvisor.

SeaWorld leads the pack with Discovery Cove

SeaWorld's Discovery Cove, where visitors can swim with dolphins, snorkel, reef dive, and take underwater walking tours, topped the U.S. list and, for the second year in a row, the worldwide list. SeaWorld Orlando and Busch Gardens in Tampa placed seventh and 10th on the U.S. list.

Despite the accolades from guests over the past 12 months, SeaWorld had a lackluster first quarter this year, bringing in 11% less revenue than it did in the first quarter of 2013. The company said that was due in part to Easter falling late this year, which affected the timing of schools' spring breaks. That timing quirk plus negative publicity sparked by the documentary Blackfish, lots of rain in Orlando, and unusually frigid temperatures in San Antonio contributed to an overall 13% drop in first-quarter attendance.

But with the world's most popular theme park for two years running, SeaWorld is forging ahead, investigating the possibility of developing multiple parks in the Middle East, where tourism and development are booming. And if the company can develop more offerings like Discovery Cove that aren't centered on controversial orca attractions, it's likely to find a better reception from the park-going public.

Harry Potter attractions rake in the galleons for NBCUniversal

NBCUniversal's Islands of Adventure park in Orlando was voted second on the U.S. list and third worldwide. Universal Studios Hollywood rated ninth in the U.S. and Universal Studios Singapore ranked eighth worldwide. The company's theme parks segment had positive first-quarter results in spite of the Easter and spring break timing changes -- attendance was stable compared to the first quarter of 2013, and guests spent more, leading to a 5.4% rise in revenue for the quarter.

The company is banking on magic for more visitors to its parks in Orlando and Osaka, Japan. The Osaka version of "The Wizarding World of Harry Potter" opened July 15 and is fully sold out for the first several days. NBCUniversal spent $444 million building the attraction, which it expects to draw an extra 2 million visitors per year from around Asia. Earlier this summer, the new Harry Potter Diagon Alley attraction at Universal Orlando Resort was an instant hit, with visitors waiting up to six hours for a spin on the "Escape from Gringotts" ride.

The attraction of experiencing fictional film worlds firsthand goes beyond the Universal-branded parks. NBCUniversal has also partnered with one of the only non-U.S. owned theme parks on the top 10 worldwide list. Brazil's Beto Carrero World features Universal Studio's Velozes & Furiosos car show, based on The Fast & The Furious film franchise. Beto Carrero also has a show based on Dreamworks' Madagascar.

Disney banks on new planning tools and new park plans

If any company has mastered the art of translating fiction to real-life experience, it's Walt Disney. The Disney brand earned the most top 10 spots in the U.S.: its Orlando-based Magic Kingdom, Hollywood Studios, and Animal Kingdom parks plus Disneyland in Anaheim, Calif. All four of those parks also made the top 10 worldwide list.

Disney reported a parks and resorts revenue increase of 8% in the second quarter and an operating income increase of 19%. Its new MyMagic+ trip-planning tool integrates visitors' real-world Disney experiences with their digital lives by blending social media functions with attraction reservations, mobile tools, and vacation calendars. MyMagic+ is already used by about 75% of Walt Disney World guests -- and all indications are that guests who plan ahead spend more time in Disney territory.

Disney has also stepped up its investment in the Shanghai Disney Resort that's slated to open next year, putting another $800 million into the project. Company officials cited rising Chinese incomes and a vast potential market -- 330 million people within 3 hours of the park -- as reasons to ramp up its commitment.

With Disney's Shanghai park, NBCUniversal planning to draw millions more guests to Osaka with its Harry Potter attraction, and SeaWorld checking out its Middle East options, the American version of fun will continue to top the charts at home and internationally. And until someone figures out a way to make the theme park experience go viral on YouTube, it looks like the first movers will maintain their in-real-life advantage.