Hi Debbie:
There are currently
four Disney World Value Resorts: All-Star Sports, All-Star Music, All-Star Movies, and Pop Century Resort. During the summer of 2012, a new Disney Value Resort will open,
Disney's Art of Animation Resort. I've found that the three All-Star Resorts are pretty similar, with the only real differences being theming. Others I know have similar experiences. The one major difference is that All-Star Music features family suites that sleep up to six guests and feature a separate bedroom, a pull-out sofa in the living room, two bathrooms and a kitchenette. When the Art of Animation Resort opens, it will feature 1,120 family suites.
At least until Art of Animation opens,
Pop Century is generally considered the "best" value Resort. The Resort features three pools, a kid-friendly play water splash fountain, and an expansive food court. The bus service at Pop Century is also considered to be the best as the Resort generally doesn't share its bus route with other Resorts (though that is always subject to change).
Enjoy your vacation.