The best lunch in the MK area IMO is Kona. I also like The Wave but usually do dinner there instead. The only places in the MK I think are worth the money are Crystal Palace and Plaza Restaurant.
There is really no bad place to eat of the ones you've listed. Take a look at the menus and see if any one of them appeals more. I see you haven't listed lunch at CRT....have you been through the "Castle Experience"? If not, that would be on my list for a dining plan; you don't have to have a child along to enjoy it!
We loved The Plaza this past December for lunch especially dessert. We had lunch at Kona also during our trip and that was wonderful too. We have ate at WCC but it was for dinner and it was a very long wait for us but we enjoyed the food. We are a family of all boys so its sometimes hard to pick a restaurant everyone likes. The Plaza was a hit for everyone!!!! Happy Planning!
we love the Plaza - but if you want to get your money's worth for your dining plan..Kona (on the monorailfrom MK) or Whispering Canyon (a fun boat ride away from MK)
Check out the menu's and see what your family would enjoy!