#4 Xanadu 2.0, Seattle, Washington
Next up in the list is an house from Xanadu 2.0, Seattle, Washington. And guess who’s house is this? Bill gates! Microsoft founder and philanthropist Bill Gates has a net worth of around $67 billion, which consistently keeps him among the 5 wealthiest people in the world. Not surprisingly, his Seattle home Xanadu is a high-tech showcase valued at over $120 million in 2012. Besides housing an impressive library with a domed reading room and a 2500 square-foot gym for working out in style, the mansion on Lake Washington has a pool with an underwater music system.