Forgotten Realms Campaign Setting

The 3rd edition D&D version of the campaign setting updates the overarching meta-plot and is absolutely packed full of flavour and added rules material for 3.0e, and so it has a little bit for everyone. For players there are new prestige classes, special rules for creating characters with additional forgotten realms specific details such as region of birth, new spells and clerical domains and an awful lot of details about the deities and the planar layout; which differs significantly from the Greyhawk standard laid out in the core rulebooks.
For DM's there are enough plot hooks and ideas for dozens of full length campaigns spanning the length and breadth of Faerun and beyond, from the independent dale-realms to the frozen north, the mysterious and dangerous eastern kingdoms to the steamy Chultan jungles, the pirate-infested islands to the new world across the sea.
For everyone there is a wealth of setting materials detailing every major area of the Forgotten Realms (though there is little on Maztica or Kara-tur), including major adventuring sites and political issues, and, of course, detailed statistics on everyone's famous heroes and villains from the long list of Forgotten-Realms tie-in novels. (Yes, there are stats for Drizzt.)
All-in-all it provides a well-detailed overview and everything required to run a 3.0e forgotten realms game. For those playing 3.5e, you'll need the 'Player's Guide to the Forgotten Realms' which updates the setting to the new rules, but for setting material this book remains unmatched amongst any I've yet come across, and a worthy addition to the bookshelf of any fan.