Definitely go with the butter, and eat as much as you want. Don't believe all the "saturated fat is bad for you" crap out there. Here's an excerpt about butter from a really great article smashing all the myths and misinformation about saturated fat. Read the rest whole thing to see how bad that "healthy" unsaturated margarine spread is for you. Then go eat some butter!
http://www.mercola.com/2002/aug/17/saturated_fat1.htm
Fat-Soluble Vitamins: These include true vitamin A or retinol, vitamin D, vitamin K and vitamin E as well as all their naturally occurring cofactors needed to obtain maximum effect. Butter is America's best source of these important nutrients. In fact, vitamin A is more easily absorbed and utilized from butter than from other sources.61 Fortunately, these fat-soluble vitamins are relatively stable and survive the pasteurization process.
When Dr. Weston Price studied isolated traditional peoples around the world, he found that butter was a staple in many native diets. (He did not find any isolated peoples who consumed polyunsaturated oils.) The groups he studied particularly valued the deep yellow butter produced by cows feeding on rapidly growing green grass. Their natural intuition told them that its life-giving qualities were especially beneficial for children and expectant mothers.
When Dr. Price analyzed this deep yellow butter he found that it was exceptionally high in all fat-soluble vitamins, particularly vitamin A. He called these vitamins "catalysts" or "activators." Without them, according to Dr. Price, we are not able to utilize the minerals we ingest, no matter how abundant they may be in our diets. He also believed the fat-soluble vitamins to be necessary for absorption of the water-soluble vitamins.
Vitamins A and D are essential for growth, for healthy bones, for proper development of the brain and nervous systems and for normal sexual development. Many studies have shown the importance of butterfat for reproduction; its absence results in "nutritional castration," the failure to bring out male and female sexual characteristics. As butter consumption in America has declined, sterility rates and problems with sexual development have increased. In calves, butter substitutes are unable to promote growth or sustain reproduction.62
Not all the societies Dr. Price studied ate butter; but all the groups he observed went to great lengths to obtain foods high in fat-soluble vitamins-fish, shellfish, fish eggs, organ meats, blubber of sea animals and insects. Without knowing the names of the vitamins contained in these foods, isolated traditional societies recognized their importance in the diet and liberally ate the animal products containing them. They rightly believed such foods to be necessary for fertility and the optimum development of children.
Dr. Price analyzed the nutrient content of native diets and found that they consistently provided about ten times more fat-soluble vitamins than the American diet of the 1930's. This ratio is probably more extreme today as Americans have deliberately reduced animal fat consumption. Dr. Price realized that these fat-soluble vitamins promoted the beautiful bone structure, wide palate, flawless uncrowded teeth and handsome, well-proportioned faces that characterized members of isolated traditional groups.
American children in general do not eat fish or organ meats, at least not to any great extent, and blubber and insects are not a part of the western diet; many will not eat eggs. The only good source of fat-soluble vitamins in the American diet, one sure to be eaten, is butterfat. Butter added to vegetables and spread on bread, and cream added to soups and sauces, ensure proper assimilation of the minerals and water-soluble vitamins in vegetables, grains and meat.