Preheat oven to 400°.
Bake potatoes at 400° for 1 hour or until done, and cool slightly. Cut each potato open; carefully scoop pulp into a bowl, leaving shells intact. Add cheese and sour cream to pulp, and mash; stir in onions and salt.
Increase oven temperature to 450°. Stuff shells with potato mixture, and sprinkle with paprika. Place on a baking sheet; bake at 450° for 15 minutes or until thoroughly heated.
Microwave Directions: Pierce potatoes with a fork, and arrange in a circle on paper towels in microwave oven. Microwave at high 16 minutes or until done, turning and rearranging potatoes halfway through cooking time. Let stand 5 minutes. Stuff potatoes as directed above, and microwave at high 5 minutes or until thoroughly heated.