What is a good source for unsaturated fat?

According to American Heart, some of the best sources of polyunsaturated fat can be found in plant sources such as sunflower, corn, safflower, nuts, soy, sesame, and seeds. Foods that contain high levels in polyunsaturated fats includes fish that contains plenty of fish naming herring, salmon, trout and mackerel. Many vegetable oils contain high polyunsaturated fats such as corn oil, soybean oil and safflower oil.