Some that I have enjoyed in the past are...
Cosmic Rays in MK
Liberty Inn in Epcot
Pizza Planet in MGM....
We have tried Flame Tree BBQ in AK once and it was ok...not something I'd make a point that we have to back to again, but I would eat there again if I were hungry while at AK.
**Edited to add I just saw the "and why" part of your question.
CR, I enjoyed the burgers and fries there, and I like the topping bar.
LI, Again, a good toppings bar and enjoyable burgers & fries. My kids who dont eat much devour the large hot dogs there. And well, it gts DH's vote because they serve Sam Adams, his favorite.
PP, For some reason their salads always hit the spot for me. I used to think their pizza was just ok but it has gotten better over the past few years. I'd rate it as pretty good now(but I know many dont share my opinion).
FT, the kids hot dogs were sort of chewy and shrivlled...like they had been microwaved. I had either a pulled pork or pulled beef (I forget which they have) sandwich which I thought was pretty good.