Let's see. 1st edition advanced DnD, 2nd edition, 3.5 edition. I still have all the 3.5 materials and most of the 2nd edition stuff. Rest went missing over time. I've done Greyhawk and Dragonlance stuff but mostly I did Forgotten Realms (Faerun) stuff. The most important stuff I have is my box containing my massive collection of NPCs I've written over many years as a Dungeon Master from 2nd edition on. I've got unique colourful characters to draw upon for whatever profession or reason if I run adventures.