I thought this was interesting information so I decided to post it.  The top 10 theme parks in the world and how many people visit a year:
1.  Magic Kingdom - Walt Disney World, Orlando, Florida  -17,142,000
2.  Disneyland - Anaheim, California  - 16,140,000
3.  Disneyland, Tokyo - 13,996,000
4.  Tokyo Disney Sea  - 11,930,000
5.  Disneyland Paris -10,990,000
6.  Epcot - Walt Disney World Orlando, Florida -10,825,000
7.  Animal Kingdom - Walt Disney World, Florida  - 9,783,000
8. Hollywood Studios - Walt Disney World, Florida - 9,699,000
9.  Universal Studios - Osaka, Japan  - 8,500,000
10. Islands of Adventure, Universal, Orlando - 7,674,000
I got this information from Yahoo Travel to give proper credit.