Preheat oven to 350°. Pierce potatoes and bake on a baking sheet until tender, about 1 hour. When cool enough to handle, cut a thin slice off the top of each potato and discard. Scoop out pulp, leaving a thin shell., In a small bowl, mash the pulp with butter, milk and salt. Stir in cream cheese and sour cream. Spoon into potato shells. Sprinkle with paprika., Place on a baking sheet. Bake, uncovered, until heated through and tops are golden brown, 20-25 minutes. If desired, sprinkle with parsley and green onions.