My daughter's cute little pink croc on the monorail track when she was 3yo -- oops. Luckily, I always pack two pairs of shoes for each kid. And I think my husband has lost enough pairs of sunglasses to open up a little stand and sell them if they were all recovered. That's how he rolls.
I lost a pack on Dinosaur! early one morning. I was sitting on the right side and the rest of the family to the left. When we went to get off the pack was missing. We informed the CM who said if they found it they would bring it to guest relations. We decided to ride again this time I was on the left and about 1/3 of the way into the ride there set the pack. Sure enough at closing (about 5pm 10+ years ago) a couple of CMs walked up to Guest Relations with our pack!