The crossroads shopping plaza, about 1 mile from DTD has a seafood restuarant called "the crab house". It is great, a little pricey but some really great seafood. This is a must do whenever we're at Disney. It's close enough that you can cab it.
The Crab Shack is NOT in the Crossroads shopping plaza. It is located about a half mile down 535 on the left side next to Chilis and the Macaroni Grill.
535 has many of the popular chains. Just outside of DD is Dennys (yuk!) Burger King and Olive Garden. There is also a Black Angus Steaks. Turn right onto Palm Parkway and there is a Pizza Hut and a Chinese restaurant.
At the corner of Winter Garden-Vineland (aka CR 535) and SR 535 is a 7-11. Right next to the 7-11 is an Orlando Ale House. They have great food, the prices are right and the best wings in town. They also have a kids menu.
Restaurants in the Crossroads are Perkins, McDonalds, Pizzeria UNO, Taco Bell, TGIFridays, Wild Wings, Red Lobster, Marble Stone Creamery (not a restaurant, but ice cream)
Located on 535 to the right as you are leaving downtown Disney- just past the I 4 exit/entrance ramps are Landrys Seafood on the left, next to Lone Star Steakhouse. Across the 535 and a tad further down is a Chik Fil A, Benigans, Wendys,
Try to stay off of I Drive aka International Drive. For restaurants anyways. They will be pretty crowded, plus traffic and parking just for eating is too much bother when you can find it somewhere that is easier to get too. IMO.