Combine margarine, 2/3 cup granulated sugar and brown sugar in a mixing bowl; beat until creamy. Stir in peanut butter, egg and vanilla; mixing until well-combined. Stir in flour and baking soda; mix well. Shape dough into 1-inch balls, then roll in 3 to 4 tb sugar, coating thoroughly. Place 2 inches apart on ungreased baking sheets. Bake in a 350-degree oven for 10 to 12 minutes or until golden brown. Remove from baking sheets; make crosshatch marks with fork; cool on wire racks.