Hollywood Studios:
Fairfax Fare has some large chicken & ribs or chicken & brisket combo meals and a half chicken meal. The combos are only a 1/4 chicken portion, but with fries and cole slaw it's enough to split.
We also split the sandwich at Starring Rolls, since the yummy dessert cupcakes are very filling, even 1/2 of one!
Toy Story Pizza Planet has a pizza/small salad combo. Not too big but OK if both aren't too hungry and just want a bite.
Animal Kingdom:
Pizzafari, same pizza for one with a small salad as at Toy Story.
We've also split the hot Italian sandwich, but it's not huge.
Rib or chicken plates at Flame Tree.
Magic Kingdom:
Definitely the 1/2 chicken & ribs combo platter with green beans and mashed potatoes at Cosmic Rays.
Double bacon cheeseburgers at Pecos Bills, though I hate those new wheat buns

. I wouldn't bother with ordering an extra bun, just cut the thing in half, they are filling, esp. with a few extra items from the fixin's bar.
Epcot:
Sunshine Seasons half chicken plate or pork chop plate, it's a big chop. Also several meal size salads. Chicken ceasar there is better than at other locations. Sandwiches to split too if you want a light bite.
Morocco definitely. Those schwarma platters have plenty on them.
At the France bakery you can get a small (like 3 bites) ham & cheese croissant for a snack credit. If we have snack credits to burn we get two of those and a chocotate mousse to split for 3 snack credits total.
Not sure of the nacho plates at the new Mexico Cantina CS, but seems that would be a CS big enough to split too if the size is normal and not single per person sized. Anyone got a picture of those from the new CS?