Welcome to DC! Caver has given you some very good advice. Get the Unofficial Guide as soon as possible. Make it your nightly reading. You will get many, many opinions here (because that's what we love to do
) Maybe you could help us a bit by telling us what kind of food you like, what you would like to try, etc.
Epcot's World Showcase enables you to try foods from many different countries. Do you have a special, favourite ethnic choice? Do you want to dine with the Disney characters? Are you looking for a child-friendly environment, or one that's geared more towards adults. If this all seems overwhelming, don't worry. We love to help first-timers sort things out. We live vicariously through others successful Disney trips! That being said, here are a few of my favourites:
Le Cellier (Canada, Epcot)
San Angel Inn (Mexico, Epcot)
Spoodles (The Boardwalk)
Earl of Sandwich (The Marketplace, Downtown Disney)
O'hana (The Polynesian)