Put a fireplace, a Christmas tree and a plate of cookies in one room, then enable the move_objects on code. Delete your Sims before midnight. When Santa Claus appears, he will give you one big present, then he will start filling your house with wrapped gifts. After he has finished as many gifts as there are Sims, plus one more, click on your Sims so they reappear in your house (or the game will freeze). Leave the game on speed 3 for awhile until Santa finishes covering everything with presents.