Inside MK: BOG (though you probably already have that booked), Columbia Harbour House, the 2nd floor can be very quiet, Cinderella's Royal Table has great atmosphere.
CR/Poly/GF: The atmosphere at any of the signatures are excellent, especially Cali Grill in The CR, and Ohana in The Poly. Victoria and Albert in The GF has probably the most romantic atmosphere, but I don't know if starting at $185 per person (before tax and tip) is within your budget.
Inside Epcot: Biergarten has a great German Oktoberfest feel to it. Rose and Crown is a very British Pub. Chef's de France will take you back to a fine French restaurant. Restaurant Marrakesh will transport you to Morocco for a meal. For Counter Service, just slip into a country where you like or are intrigued by the food. Just stay away from China, their stuff is terrible. The strip mall by your house serves better Chinese food.
BC/YC/BWI/Swolphin: I'm not sure about their TS restaurants outside of Yachtsman, which is a signature and serves good steak in a upscale setting. The Swan and Dolphin have great restaurants in there. Bluezoo and Shula's get raved about a lot. For CS, Beaches and Cream is tough to beat. Lots of ice cream in a '50s soda shoppe feel. They even serve something called a "Kitchen Sink" which is everything they have in a huge bowl! They even unload an entire can of whipped cream on top!