picture disc in Muriel's collection (31 items)
From the first EP to The Allfather Awakens, many Amon Amarth albums were released as picture discs. The early German Metal Blade ones, from Once Sent from the Golden Hall to Twilight of the Thunder God, were each limited to 500 numbered copies, and I have most of them along with their (mostly white!) test pressings.
Some copies hold small mysteries: unnumbered picture discs for The Avenger and Fate of Norns, a Twilight of the Thunder God marked "XXX" instead of a number, and Deceiver of the Gods copies whose European and US stickers got mixed up at the plant. Promo copies or leftover stock? If you know more, let me know!
My favourites: the shaped picture discs released by Church Of Vinyl for Guardians of Asgaard, War of the Gods and Warriors of the North, each hand-numbered and limited to 666 copies, and especially their rare uncut promo versions, showing the full disc before it was cut into shape.