As of my last update in January 2022, the most expensive hotel in the world was The Royal Penthouse Suite at the Hotel President Wilson in Geneva, Switzerland. This luxurious suite is known for its opulence, stunning views of Lake Geneva and Mont Blanc, and extensive security features, including bulletproof windows and a private elevator. The nightly rate for this suite can reach tens of thousands of dollars, making it one of the most expensive accommodations globally. However, please note that the rankings and prices of luxury hotels may change over time due to various factors such as renovations, changes in management, and fluctuations in the hospitality industry.