DiverXO
When you ask a Madrileño about a remarkable food experience—something that stirs the senses beyond feeding one's appetite—DiverXO is the first name you'll hear. The take-no-prisoners tasting menu incorporates a dizzying array of international ingredients and chemical processes. Getting a table at this foodie shrine is akin to scoring a ticket for the Super Bowl, so plan well ahead—there's an online reservation system that requires that you to pay in full in advance.