Advent Calendar: The Star Wars Holiday Special (1978)
Traditionally regarded as the worst of all possible Star Wars tie-ins, this is the infamous "Star Wars Holiday Special" (1978). Mercifully lost for decades, it was re-posted on the internet several years ago, probably by the same people who think goatse is the height of hilarity. I make it a point to share the pain with others every year.
In a rare display of sense, Amazon does not make this item available at all, although if you're a dedicated masochist you can request to be notified when it comes out on DVD.