Our favorite place is Sweet Tomatoes. There is one in the Crossroads shopping center right across 535 from the DTD hotel strip. It is a wonderful and affordable buffet that has every imaginable salad fixing as well as prepared salads. There is also a pasta station, potato station with toppings, soup station with half a dozen homemade soups, fresh baked breads and dessert bar. I think it is $8.69 per person which is a great value.
As for sit-down restaurants, that shopping center also has a Tex-Mex place, a Bahama Breeze and a couple of others. For counter service or quick serve, there is a Flipper's pizza and they are building a Moe's (counter service Mexican - very tasty and healthy - not Taco Bell garbage). There is a Perkins down the street to the left also and a Waffle House to the right. Those are probably the closest options.