What is your favorite low-calorie but highly satisfying food?

I'm looking for foods that are lower calorie, but still satisfy my hunger. I could eat salads all day long and still be hungry. I've heard of an index called the satiety index, which measures how satisfying a food is, for a given amount of calories. Boiled potatoes, oatmeal, oranges, and apples scored well. That means you don't need to consume as many calories of those foods to feel full. What works best for you? I especially want to find snacky foods that will fill me up, but not be loaded with calories.