GH.... Wilderlands..
And surprisingly, FR over the years has become my fave setting to game in, even beating out my beloved Pre Wars GH (a heartfelt, "sorry", to Gary).
I have used FR for OD&D, 3.0 and 4e in the past few years. I use the OGB as my base. It is extemely easy to modify without having drastic effects elsewhere. If I want more detail on a certain region or power group or whatever, there are 10 books available to try. If I need a map of a certain place, chances are one is available. If I do not have the time or inclination to make stuff up, I can usually find one iteration I like among the several different "eras".
That said, my base is strictly OGB,..I have cut out all the BS. No ToT, No Drizzt or Drow running all around or under like colonies of ants, No Spellplague, no Lame Novels ,no "lets make it more angsty and powerful" 3e revisions, etc. No Chosen, no Spellfire, No NPCs becoming Gods or whatnot. My FR is very much a S&S or Wilderlands type of thing , just by my style of DMing I guess. I do use a couple 2e resources and one 3.5 resource for historical and regional details when I have liked what I read. Oh, and that new book Ed wrote last year...the Elminsters Guide to FR or whatever..best book WOTC has put out for FR since they have owned the property.