I have sitting in line of sight of my comp here, the "old" blue D&D rulebook (the single non-advanced rules for levels 1-3 or 4, the one that came out after the original small softbound 3 book ruleset). Far as AD&D goes, I never progressed beyond the original AD&D - The classic 4-book hardbound rules: Dungeon Masters Guide, Monster Manual, Players Handbook and Dieties & Demigods were my staple rulebooks for years, along with the Dragon magazine updates. I was still into it for Unearthed Arcana, Fiend Folio, and Monster Manual 2, but I think at that point they began the second edition with a whole new series of hardcovers and I stopped playing. Ive still every piece of RPG investment Id made as a kid and a teenager. Its a blast to thumb thru the old dragon mags to this day :)