San Francisco's SFO Museum offers no fewer than 20 free exhibitions inside the airport at any one time. Meanwhile, aiports in Miami, Albany, NY, Minneapolis, Portland, St. Louis and elsewhere offer a rotating schedule of free museum-quality art and history exhibits throughout the year.
Austin-Bergstrom International and Seattle-Tacoma International airports each present more than 20 free music performances each week and, at Milwaukee's General Mitchell International Airport, passengers can play ping pong for free.
Free water: bring your own bottle