Hi Leigh!
Thank you for sending this in. It's nice to answer a question from a fellow citizen of Maryland!
In my opinion, there are two places to get great seafood in Walt Disney World.
Narcoossee's in the Grand Floridian and the
Flying Fish Cafe at Disney's Boardwalk. Both are Signature Dining restaurants and both have fantastic seafood.
Of the two, I probably like Narcoossee's a little better, but that's really due to its location as opposed to the quality of its food offerings. It has a great location on the Seven Seas Lagoon and you can even see the Magic Kingdom fireworks from there.
For a Counter Service Restaurant that is outside a theme park, I recommend Cookes of Dublin and Earl of Sandwich in Downtown Disney. Inside a theme park, I recommend Pecos Bill in the Magic Kingdom, Sunshine Seasons in the Land Pavilion In Epcot, Flame Tree Barbecue in Animal Kingdom, and Starring Rolls Cafe in Hollywood Studios. However, my favorite is Sunshine Seasons. It's wonderful!
Have a magical vacation!