Bought last week, but unboxed and tested today: A standard cheap plastic airbed, GampingGaz-branded. Chosen primarily on the basis of width and thickness: barakta's shoulders, for the preservation of (when motor-assisted camping in a tent-you-can-stand-up-in).
While the gear freak in me would much prefer an Alpkit Dozer or something, prior experience suggests that this is actually the best option for a decent night's sleep with a minimum of painkillers and crunchiness in the morning (which translates to ability to do things like ride bikes). It's also a fraction of the price, and a fraction as durable. Thermal insulation can be had in the form of heavy sleeping bags. It'll do.
I'm quite impressed with the valve design, which while not entirely barakta-friendly does allow you to disconnect the pump (yes, you need one of those too) without accidental deflation.