Preheat oven to 350 degrees F (175 degrees C).

To Make Crust: In a medium bowl, mix together margarine, pecans and graham cracker crumbs. Pat into a 9x13 inch baking pan. Bake in preheated oven for 20 minutes or until lightly browned; allow to cool completely.

In a medium bowl, beat together cream cheese and confectioners sugar until smooth. Fold in 1 cup of the whipped topping. Spoon mixture into graham cracker crust.

Prepare chocolate and vanilla puddings with milk as per package directions. Allow pudding to set before pouring on top of the cream cheese layer. Spread remaining 3 cups of whipped topping over pudding layer; swirl melted chocolate throughout whipped topping.

Cover and refrigerate for about an hour. For leftover pie, keep frozen in a tightly covered container. When ready to eat, just cut off a piece and allow to thaw; keep rest frozen.