I saw him on a New Year's Eve during the late '80s. I'm not totally sure what year it was, somewhere around '87-'89. He was by the Matterhorn queue on the Fantasyland side, wearing a blue military jacket, black fedora, sunglasses and white glove, surrounded by kids and a couple bodyguards.*
(*This is how I remember it, but I could totally be wrong about the details.)
Please share your MJ@DL sightings!