The Fragonard room at the Frick Collection with its amazing French furniture and Sevres porcelain.
Marie Antoinette's Chamber at the Palace of Versailles. Versailles is an interesting case as you are allowed to click beyond the Hall of Mirrors and out into the gardens. But alas, you cannot navigate your way to the Petit Trianon or the Queen's farm folly, the Petit Hameau. Perhaps there will be an update.
Greek red-figure vases from the first floor of Russia's Hermitage State Museum.
The Robert Adam designed dining room from Lansdowne House now in The Metropolitan Museum of Art. In addition to European Paintings, the Met saw fit to include Medieval Art, part of European Sculpture and Decorative Art, the American Wing, and African Art.
The navigation is a bit tricky and sometimes you pass through walls accidentally into other rooms. Also I got a bit lost in the garden at Versailles and found it hard to navigate back to the chateau....but is that really such a bad thing? Enjoy!