Once asking a staggering $114 million, this opulent Upper East Side mansion is now on the market for $79 million. The townhouse belongs to billionaire Vincent Viola, best known for owning the Florida Panthers; he purchased this townhouse back in 2005 for a comparatively modest $20 million. The 19-room mansion was designed by William Bosworth, the Gilded Age architect who designed the Rockfeller Estate, Kykuit. Additions by Viola include a heated saltwater pool, a theater with red velvet seats, and a dining room inspired by Versailles.