If you have time be sure to take your family to dinner at the Polynesian (spelling? a resort on the property, which can be reached by the rail) and go to Ohanas... It is all you can eat steak, shrimp, chicken, and pork served on skewers and it is quite possibly the best food I've had throughout all Disney... Alot of your expense came from the place you're staying at. Next time stay off the property. I always stay at the Radison close to Disney (with my Florida state resident discount it's $70/night with nice/clean room).
As an adult I like Epcot the best ~ it has good places to eat and some gift shops. It's a more relaxed park out of the 4 and the Space and Test Track were enough in the rides department for me.
Most kids 9 - 16 like MGM the best since they have the best rides/ rollercoasters
Magic Kingdom - good for little kids but sucks for everyone else
Animal Kingdom - would be good for the last day or extra time... The have a decent Jurasic Parkish ride...
The price of your vacation is onething but labelling it expensive is only relative to the value that you and your family derive from the trip. If you take advantage of it the right way and plan it out that what you pay isn't half of what the trip is really worth!