I recently picked up Quantos Possunt Ad Satanitatem Trahunt too, which is very good.
*edit* I now also own Under The Sign Of Hell 2011 and Instinctus Bestialis
Bathory - Bathory
Bathory - Under The Sign Of The Black Mark
Old Sorcery - Clandestine Meditation In Two Chapters
Choosing Death: The Improbable History of Death Metal & Grindcore expanded edition (book)