Our favorite burgers at DCA are at Taste Pilots Grill and pizza at Boardwalk Pizza & Pasta. At DL, it would probably be pizza at Pizza Port. I can't remember any good burgers. The place where they have the Jedi Academy sells burgers, but they were just ok, not really great.
I like Daisy's Diner pizza in Toontown! It is a supersize individual pizza, but just cheese or pepperoni for toppings. The crust is thick and chewy; I don't love flat bread/crispy pizza. It is different than the kid's pizza at Pizza Port/Boardwalk.
I haven't had pizza there that I like-maybe because I've only eaten at Pizza Port and that scared me from trying it anywhere else.
Burger gotta be Taste Pilots. I love putting the topping bar so I can get it exactly how I want with as much "goo" as I want-plus then I can get some mayo for my fries without getting weird looks. Right now it's the only burger on our plan to eat when we go down.
If by Disneyland you mean "Disneyland Resort" then I wouild say Rainforest Cafe has the best burgers. Inside the parks the best burgers are at Taste Pilots Grill.
Best pizza? Redd Rockett's at DL is OK and Boardwalk is OK. I have never eaten at Naples at DTD but I have at Epcot and that was pretty good. So I would go to Naples if I wanted pizza.