Minecraft wiki entry for Shelters, associated text: A room with framed trophies from your many victories: your first ghast tear, the enchanted sword you killed a wither with, your first nether star, a block of emerald, etc. Use signs as plaques to mark the origin and perhaps the date of your trophies, give it fancy glowstone lighting, and have a pride-of-place shelf for a wither skeleton skull or perhaps even the Dragon Egg.