There's a website devoted to the topic:
http://www.sleepinginairports.net/

For those who say they'd never sleep in an airport, sometimes there just is no choice. Years ago I was connecting (CLE, I think) on CO. Blizzard was moving in, we boarded and waited around 3 hours on a taxiway waiting for a hoped for break in the weather that never came. By the time we got back to the gate and disembarked, the blizzard was pretty much in full force. I was top level elite with CO at the time, but we were one of the last flights to return to the gate, and they apologized but said the hotels were full by then. In any case, the hotel shuttles were no longer running, and cabs were very scarce.

These days I would know better than fly into the teeth of a blizzard, but I was a fairly new business traveler then and didn't know to check and didn't realize my connecting city was expecting bad weather.