Iceberg lettuce is one of the most common choices for the foundations of a salad, but it's not a smart one. This pale green vegetable is neither very nutritious, or filling. If you're going to have a strong foundation for your salad you're better off to choose the darker kinds of lettuce such as romaine, raddicchio, red leaf (mizuma, tango, and lolla rosa, too, for the connoisseurs). Greens like arugula (a.k.a "roquette" or "salad rocket"), spinach, kale, watercress, endive, bok choy, and bean or alfalfa sprouts will also powerhouse your plate, fill you up, and provide excellent nutrients.