Left my jacket on plane (not returned to me at end of flight after leaving it with FA), reported it to Concierge on arrival, and got it back 5 months later delivered to my home in a beaten up cardboard box, but no worse for "wear". Apparently the colour of the jacket matched AC uniforms, and everyone assumed it belonged to a crew member. My jacket probably qualifies for a MM award.
Also, dropped a credit card on a flight in Mexico and learned about it next day when it seems I bought a pretty cool bicycle in a local Walmart.