Rarest items in your collection or in your want list?

For several years I was looking for Thomas - You Will Fly vinyl and finally found it recently, so that must be it
I don't really have anything in my wantlist now that tops that.

Personally, however, I think what collectors call "rarity" is quite a silly notion since the concept almost only is defined by the sellers calling an item rare if they think the item is rare. Really if you think about it a rare item would be an item that only exists in very few copies and not something produced in several hundred copies but rarily sold, in that sense you could probably call a promo rare.