Hi Matthew,
I'm a big fan of the Disney Dining Plan so I'd be happy to help you with your question. Quick service restaurants are found throughout the Disney theme parks, resorts, and shopping areas. These are restaurants where you order your food at a counter and then select a table on your own. By comparison, in table service restaurants a Disney host or hostess typically seats you and then a Cast Member brings your food to you after you order from the restaurant's menu. Tipping is appropriate at table service restaurants, but not quick service restaurants.
To give you some examples of quick service restaurants, here are a few of my favorites organized by their location:
Min & Bill's Dockside Diner in Disney's Hollywood Studios
Columbia Harbour House in the Magic Kingdom
Roaring Fork in Disney's Wilderness Lodge
Flame Tree BBQ in Disney's Animal Kingdom
Capt. Cook's in Disney's Polynesian Resort
Sommerfest in Epcot's Germany Pavilion
There are so many wonderful choices when it comes to quick service restaurants. There is a more comprehensive list
here.
Have an amazing trip to Walt Disney World!
Jill