I'm surprised no one's mentioned the offerings at Tangerine Cafe in Epcot. They have a veggie platter that's especially good. Another good option if some in your family want plain ole' Hamburgers and stuff is the salad at Pecos Bills. You can order it with or without chicken. I always get it without chicken, add a few grilled onions from the fixins bar, and it's so huge, I can't finish it. Yummy!
Oh, I just remembered that I had a great antipasto salad that once again you can order with or without meat. I ordered it without meat and it was delicious.