I cannot recommend a specific brand to you. However, look for a margarine with a liquid oil as the first ingredient on the food label. Oils that are high in polyunsaturated fat are safflower, sunflower, soybean, corn, and cottonseed. Polyunsaturated fats help lower blood cholesterol levels. The margarine will also contain partially hydrogenated vegetable oil (usually soybean) to harden the margarine and keep it in a stick form. Look at the ingredients of the margarine you are using.
A controversy about margarine brands is trans fatty acids which are formed when liquid oils are hydrogenated to make stick margarine and shortening. The shape of the fat molecules gets twisted into a trans shape. Research has found that trans fatty acids increase LDL (low-density lipids which are bad cholesterol) and decrease HDL (high-density lipids which are good cholesterol). If you quit using stick margarine and solid shortening, the effect of the trans fatty acids on cholesterol will lessen after 6 months according to Dr. Kritchevsky. By the way, the new food label does list saturated fats and trans fatty acid content as it is required on the current food label.
Polyunsaturated margarine, if left at room temperature, will usually melt in the summer. Polyunsaturated fats are usually liquid at room temperature. Whereas, cholesterol and saturated fat are usually solid at room temperature which is one way to tell the difference.
You should be able to find several good low saturated fat, low trans fat margarine in your grocery store. Take a look at the ingredients in your store’s brand. You don’t have to buy nationally advertised brands to find one low in trans and saturated fat.