Wow, maintaining a forum thread of this stuff would be pretty crazy... Thats why there's the huge media database at www.videohelp.com/dvdmedia. It is all run on user submissions, and has an extensive list of all the media IDs you might recieve if you buy from a certain manufacturer.
Now, I can't speak for accuracy of that list, but some manufacturers change brands a lot, some don't. There are the ones that have their own media, like Verbatim (MCC), RiData (RITEK), and Sony (usually SONY, sometimes others), and those that outsource like madmen, like Memorex, TDK, Fuji, Imation, and Maxell. Unless there's a Made In Japan label on the spindle, there isn't really a good way to know what you'll get with these brands.