Luckily there is no distinction between free dining and paid dining in terms of what the credits can be used for! (I'm guessing that FD means free dining in your post.)
MK: Dole Whip Float (Aloha Isles)
Epcot: this one is tough because there are so many good things at the Kringla, Patisserie, and Karamel Kuche.
-Waffle (Kringla)
-Chocolate Eclair (Patisserie)
-Caramel Corn (Karamel Kuche)
DHS: Peanut Butter Cupcake (or really any of the cupcakes at Starring Rolls)
AK: White Elephant Cupcake (or really any of the cupcakes at Kusafari Bakery)