Place 10 large potatoes in large kettle, cover with water and boil. Reduce heat, cover and cook for 20-25 minutes or until potatoes are tender. Drain and mash in large bowl.
Add sour cream, 4 T margarine and onions, stir until smooth and cream cheese and margarine are melted. Spread in greased 9x13 baking dish.
Melt remaining 2 T margarine, drizzle over potatoes. Sprinkle with paprika.
Refrigerate or bake immediately, covered at 350° for 40 minutes, uncover and bake an additional 20 minutes.
If refrigerated, let stand at room temperature 30 minutes before baking. Makes 12 servings.