Pierce potatoes with fork. Place on microwave-safe paper towel in microwave oven. Microwave on HIGH for 10 to 13 minutes or until tender, turning potatoes over and rearranging halfway through cooking. Let stand 3 minutes.
Meanwhile, brown ground beef in medium nonstick skillet over medium heat for 8 to 10 minutes or until thoroughly cooked, stirring frequently. Drain. Stir in spaghetti sauce and corn. Cover; simmer 4 to 5 minutes or until thoroughly heated, stirring occasionally.
To serve, cut potatoes in half lengthwise; place on 3 individual plates. Mash potatoes slightly with fork. Top each potato with 2/3 cup beef mixture. Sprinkle with cheese.