Leanne,
As soon as I start listing the top 6 restaurants, I know there will be a longer list of "
But what about X, Y, and Z?" That is the beauty of dining at Walt Disney World, there are always more great choices!
But if I had to pick 6 for your family, based on what I know of you from the question, it would be;
Of these, the last two are the real seafood suggestions.
Narcoossee's,
Fulton's Crab House,
Todd English's bluezoo, and the
Flying Fish Cafe are all also great venues for superb seafood, but higher on the price scale, so they may not be ideal for a family of 5 with younger children. Of these, Fulton's might be the best option, if you are going to be at Downtown Disney for a lunch.
I am glad to address any of your follow-up questions! Just send me a question with more information, and I can refine my suggestions!
Have a magical (and delicious) vacation!