Yesterday afternoon I flew into the world's best airport. Singapore's Changi Airport has just been voted "Best Airport in the World" for the 20th year in a row by Business Traveler Magazine. It has already won 11 "best airport" awards so far this year. Built back in the 1970s, Changi is certainly not the world's youngest, so why does it keep beating out its newer rivals? For one thing, once you land in Singapore, everything you need is right there. Yesterday, in between flights, I was able to buy supplies at a drugstore, visit the post office, and grab a fresh sandwich. After checking out the latest digital cameras, I bought a new power adapter. All my transactions were exempted from Singapore's 7% sales tax once I showed my boarding pass. On other occasions I have made use of the airport's free Internet terminals.