I like to be able to mix up products, to a) make use of good gaming materials that I like, b) keep my players on their toes (in case they own the same books), and c) because it's fun
So, for example, my version of the City of Brass would leverage these as primary and secondary source:
- Al Qadim's box set with the wonderful Dave Sutherland maps
- Rob Kuntz's "To the City of Brass" RPGA tourney
- Rob Kuntz's City of Brass manuscript (the 90,000 word version)
- Sir Robilar's City of Brass Hackmaster module (RJK and Jeff Knight)
- NG's CoB stuff (when it's released)
- Sir Richard Francis Burton's translations of the Tales of 1001 Nights
- the odd adventure in Dungeon that has caught my eye over the years as a good slot into an Arabian Nights style campaign/CoB environment
The most important item on that list is the Burton Arabian Nights stories. Not the gaming books.
My version of the City of Greyhawk is similarly multi-product based: I use the LGJ #2 (see
http://www.melkot.com/locations/cogh/cogh.html) and details from EGG's Gord novels, various auction posts from Rob Kuntz's City of Greyhawk auctions, and the Outdoor Geomorphs Walled City info as my baseline. I then supplement that with Roger Moore's Greyhawk: The Adventure Begins, the 2e City of GH box set, and a bunch of additional city supplements (Midkemia Cities, Chaosium Thieves World box set, Gamelords Haven, and the Citybook series from Flying Buffalo/Blade).