Our own Cleveland Hopkins Airport has some nice art work on the walls in some of the concourses and a nice relatively new food court but other airports have some unusual things to make your time between flights a lot more interesting.
The Heathrow Airport in England has nap rooms, cubicles with a bed and shower facilities that rent for $40 for 4 hours. Great idea for those traveling a good distance and can't sleep sitting up in a plane.
In Vancouver you can visit the large aquarium in the airport. This must be something more recent since we've been through there a few years back and didn't see it.
San Francisco, Burlington, Chicago and Dallas/Ft. Worth all have yoga rooms for those who need to work out and relieve the stress.
We found a small museum in the Athens Airport that was an interesting diversion. There is also one in the Amsterdam Schipol Airport that is an outpost of the Rijksmuseum.
I'm not a golfer but if I were this might appeal to me. There is a nine hole golf course at the Hong Kong Airport and is up to the United States Golf Association standards.
Now in all the research, I think the best find was the Singapore Airport. Wow. That's the place I want to be if my flight is canceled or delayed. They have all sorts of stuff for adults and kids including a butterfly garden, a koi pond, a movie house, lots of other gardens and horticultural displays and I found one site that says there's a huge covered slide for your amusement. Who knew an airport could be a destination?!