The quality of an airport can be subjective, sometimes. It can depend on how long you may be stuck in the airport, the airline you're flying with, and whether or not your luggage has made it with you. A frequently flying business traveler might have a completely different opinion of an airport over a family of 6 just trying to get to Disney. Because of this trying to pinpoint how good or bad an airport is might be a little difficult. There is one exception to this rule, and that's Changi airport in Singapore. In travel websites all over the world, this airport almost always ranks as one of the best, often the best.
While free wifi and clean bathrooms are certainly reasons to call this airport good, Changi goes a few steps further. Not only is the airport massive, with more shops and restaurants than most airports, it's the little additions that you find in Changi that make this airport almost comically amazing.
Say you have a 2 or 3 hour delay at the airport. Say your tablet is out of juice as well, not that it would be a problem in Changi as there are a million places to charge your gear. But say your Netflix account isn't working (probably should have set up that VPN), don't worry though, Changi has you covered. In the airport are 2 theatres, free for everybody. These aren't just boardrooms with screens, these are full sized theatres with theatre seats playing the same movies you can see on Singapore Airlines flights. They play constantly with the times marked on the outside of each theatre.
Maybe you have a bit more time on your hands, and maybe you've been thinking of visiting Singapore. Changi has you covered, throughout the day the airport offers city tours. You don't have to worry about getting back in time for your flight; they'll check your boarding pass before you go. The tours are free, yes free, and in some cases allow you to leave the bus and explore a few of the city’s prize attractions. They require no visas either; technically you haven't left the airport on this tour. There are both day and night tours available.
Ok, so you don't have enough time to see a movie, or take a tour, but you still have some time to kill. Maybe after your long flight you just need some fresh air or something to calm your jetlagged nerves. Why not walk through one of Changi's many flower gardens, including a sunflower garden and a tropical garden. If that's not enough for you, or if it's raining, you can always visit their indoor butterfly conservatory. As you might imagine, all of this is free as well. What about the kids, they may not want to hang out in the garden, they want something fun. How about a 40-foot twisty slide?
I've actually booked an extended layover at Changi just so I can visit all of the attractions. The one drawback to this airport is the sheer size, if for some reason you had a really short stop over and your gates were far apart, you might have a hard time. The good news is, if you miss your flight, you have lots to do while you wait for the next one.