This collector's list series is incredibly complete. It includes not only the books published by TSR and Wizards of the Coast, but those before TSR and those officially licensed by WotC. It also includes licensed miniatures, magazines, and other RPG-related products. The entire series will be approximately a dozen tomes, with the first ones releasing at GenCon in 2009.

UUCG: Volume One - Original D&D and Basic D&D
This first volume covers Chainmail, the first box sets (Original D&D), the next boxes (Basic D&D), all the way through the Classic D&D put out in large boxes by TSR in the 1990's, along with all of the modules produced for Basic D&D (from the B series, through Wee Warrior's products, we have it all). Also included is the Thunder Rift setting, as it was only produced for use with the Basic D&D rules.
Regular price: $15,
Sale price: $10 (plus free shipping)
UUCG: Volume Two - Mystara and Greyhawk
This second volume covers Mystara (as well as its sub settings Hollow World and Red Steel), and Greyhawk. It includes all rules, supplements, and adventures, no matter the rule system they were produced for-Basic, AD&D 1st Edition, AD&D 2nd Edition, 3rd Edition or 3.5. It also includes the Living Greyhawk Journals. And, as always, lots of promotional items are included for fun.
Regular price: $15,
Sale price: $10 (plus free shipping)