Final answer:
The greatest room in the Palace of Versailles, according to the reading, is the Hall of Mirrors.
Step-by-step explanation:
The reading describes several rooms in the Palace of Versailles, each with its own unique features. However, the greatest room in the Palace, according to the reading, is the Hall of Mirrors. This central gallery is famous for its 17 mirrored arches, which reflect 17 arcaded windows overlooking the gardens. The room is adorned with paintings celebrating the virtues and achievements of Louis XIV.