[Sue M.]

As mentioned AP does include park hopping. And a 10% merchandise discount (20% if you get the Premium AP which includes the water parks and Disney Quest).
If you are staying on site- sometimes Disney releases AP room discounts which are a little better then the General Public discount. - Sometimes.

An alternative to an AP is getting the 10 Day park hopper- it gives you 10 days park entry, plus 10 water park or Disney Quest entries. So- if your family enjoys the water parks, for 3 or 4 days sprinkled in between park days you could have a water park day, then in the evening go to DTD Disney Quest. Also, with longer stays, some people also just do a non-park resort day or 2 also to re-charge and enjoy the resort amenities.

All depends on what you want to do- And you didn't mention if you are staying on or off site. So if you are staying off site, I'd def. go with the AP because parking is free, and that can really add up over 13 or 14 days.