Sammael
Adventurer
Campaign Setting: FRCS - perhaps the best-written and presented campaign setting of all times
System-agnostic: Grand History of the Realms, Ed Greenwood Presents Elminster's Forgotten Realms
Other highly recommended FR books, regardless of your edition of choice: Lords of Darkness, Lost Empires of Faerûn, Power of Faerûn, Magic of Faerûn (to mine for magic concepts, not mechanics)
Other books I'd recommend to people regardless of edition and setting preference: Manual of the Planes, Serpent Kingdoms (can be ported to almost any setting), Lords of Madness, Fiendish Codex I & II, Monsters of Faerûn (wealth of monster lore)
Adventures: Sunless Citadel, Red Hand of Doom
Avoid like the plague: Deities & Demigods, Planar Handbook
System-agnostic: Grand History of the Realms, Ed Greenwood Presents Elminster's Forgotten Realms
Other highly recommended FR books, regardless of your edition of choice: Lords of Darkness, Lost Empires of Faerûn, Power of Faerûn, Magic of Faerûn (to mine for magic concepts, not mechanics)
Other books I'd recommend to people regardless of edition and setting preference: Manual of the Planes, Serpent Kingdoms (can be ported to almost any setting), Lords of Madness, Fiendish Codex I & II, Monsters of Faerûn (wealth of monster lore)
Adventures: Sunless Citadel, Red Hand of Doom
Avoid like the plague: Deities & Demigods, Planar Handbook