Peel and cube the potatoes; rinse then place in a saucepan and cover with water. Cook over medium heat until tender; drain. Mash.
Stir in cream cheese, sour cream, chives, garlic salt and pepper. Stir in milk to your desired consistency. Spoon into a greased 1-1/2-qt. baking dish. With a large fork, scrape the top and make lines. Melt butter and pour over top of potatoes; sprinkle with paprika if desired.
Cover and bake at 350 degrees for 35-40 minutes or until heated through.