The clear winner because every serving packs a big dose of lycopene, an antioxidant associated with lower rates of cancer and heart disease. Tomatoes also contain loads of vitamin C and a fair amount of fiber. If your child won't eat them fresh, chunked, or sliced in a salad, try lightly grilling them with a little olive oil -- lycopene absorption is actually greater when tomatoes are cooked.
Next-best choice: Carrots, for the beta-carotene, which converts to vitamin A in the body, and because kids love the crunchy texture.
Picky-eater idea: Go for tiny grape tomatoes, which are sweeter (remember to cut them up for toddlers). Try a creative presentation: Your child won't be able to resist a grape-tomato caterpillar.