Without a a doubt, absolutely the best mashed potatoes my guests and I have ever tasted. Follow the recipe exactly, and don't skip the part where you pass the potatoes though a fine seive. It's a pain in the butt, but you will be rewarded with the creamiest potatoes ever! I put the unpeeled boiled potatoes through a potato ricer, which leaves the skins behind (no peeling necessary) before pressing through the seive. This is a recipe more about technique than ingredients.
NOTE: the recipe recently seems to be missing the butter measurement - it should be "3 sticks butter".