Ultimate Forgotten Realms campaign. That blog was of course the most rad and greatly missed PLANET ALGOL blog the blog post can be found here.
On a similar train of thought I've been writing up some notes on an Ultimate Greyhawk. The idea being that this is a reboot of the Greyhawk Setting. One of the campaigns I've always wanted to run was the classic Temple of Elemental Evil, Against the Giants, and Descent into the Depths series of modules.
One of the things that often happens is that as I gear up to run this I get so obsessed over canon that I just give up. However now that I allow myself to be unshackled from the chains of canon I can just run with it and really make it my own campaign.
So I started with the village of Hommlet. I have the beginnings of some actual notes that take the village in some very radical directions from what Gary wrote. But you know what I think that's what Gary would've wanted. For us to take his toys and run with them. To make them our toys, to make it our game and play it anyway we felt was the most fun for us.