If Disney World is too expensive (I think Disney tickets are around $60/person), try Branson, MO. A lot of people think Branson is just a bunch of country music shows, but it's much much more. Go to http://www.silverdollarcity.com/ and also check out the links to Celebration City and White Water.
Branson, and the Branson area, also has music shows (including country, gospel, 50's, 60's, and 70's music), magic and variety shows, TONS of shopping, all the miniature golf you could ever want, go-carts, games, museums (including a toy museum, wax museum, Veteran's Memorial museum, the NEW Titanic Museum, and the Museum of the Ozarks which includes everything from Civil War weapons to old dolls and toys, and even the original Bevery Hillbillies car!). You'll also find guided cave tours, a zoo, an IMAX theater, and waaaay too much more to name.
I've been to Disney World, and while I must admit Disney World is the greatest theme park on the planet, Branson is a cheaper, and just as enjoyable vacation experience.
Try these links for more information:
http://www.silverdollarcity.com/
http://www.bransoncelebrationcity.com/
http://www.dixiestampede.com/
http://www.branson.com/
http://www.branson.net/
http://www.bransonshows.com/
http://www.bransonmo.com/