Ok, I'm coming out as a geek here... The other day I was in Borders with my gf, and I commented that I wished I'd kept my old D&D manuals, they'd prolly be worth something these days. This was back when all they had were the Player's Handbook, Monster Manual, and Dungeon Master's Guide. Oh, and later on they came out with Oriental Adventures, Deities and Demigods, and Fiend Folio.