We are eat in the park people, so here are a top picks for 1-credit meals at each park:
MK = Jungle Navigation Skipper Canteen
EP = Akershus (I enjoy the food and I like the characters, but if you are averse to a character meal then I'd say San Angel Inn or Biergarten for the ambiance, or Via Napoli for the food)
HS = Fantasmic package at Minnie's Seasonal Dine at Hollywood and Vine if you like characters; Fantasmic package at Mama Melrose if not
AK = Tiffins (if you are willing to spend two credits at one restaurant--it is so worth it). None of the other TS are that great, so Tiffins is really the only one I can recommend.