Have you ever slept in an airport? I have when I arrived in a foreign country in the wee hours of the morning. The reason is not to save a few bucks but to thwart the thieving vultures who emerge late at night to relieve travellers of their money.
According to the travel website A Guide to Sleeping at Airports, Changi Airport in Singapore is the best airport for sleeping followed by Seoul's Incheon, Amsterdam's Schiphol and Hong Kong's.
Know which are the worst? Well, Moscow's, Delhi's and Charles De Gaulle are some of the worst, followed by JFK and LA's LAX in USA.
In Changi, you can even eat off the pristine floor. No kidding.
Airports I have slept in: Brunei, Bangkok and Sri Lanka. Nothing remarkable about these airports.