Settings aside
1e-TSR: no best or worsts that I can recall
Best 1e- non TSR- The Inferno (Judge's Guild)
Best 2e-TSR: Complete Thief's Handbook, PO: Combat & Tactic, PO: Spells and Magic
Worst 2e- TSR: PO: Skills and Powers
Best 2e-non-TSR: Witches (Mayfair Games)
Best 3e-WOTC: Unearthed Arcana, Fiendish Codex I, Lords of Madness
Best 3e- Third party: Elements of Magic: Revised (EN Publishing), Elements of Magic:Lyceian Arcana (EN Publishing), Advanced Bestiary (Green Ronin), Psychic's Handbook (Green Ronin), Shaman's Handbook (Green Ronin), Witch's Handbook (Green Ronin), Book of Iron Might (Malhavoc), Artificer's Handbook (Mystic Eye Games), Redhurst Academy
Worst 3.0- WOTC: Deities and Demigods, Epic Handbook
Worst 3.5- WOTC: Book of Exalted Deeds, MMIV, MM5, Weapons of Legacy
Honorable Mention for Worst 3.0*-WOTC: Defenders of the Faith, Song and Silence, Sword and Fist, Psionics Handbook, Miniature's Handbook
Honorable Mention Worst 3.5 *-WOTC: Races of Destiny, Races of Stone, Races of the Wild, Complete Adventurer, Complete Divine, Complete Champion, Complete Scoundrel, Races of the Dragon, Expanded Psionics Handbook, PHB2, Magic of Incarnum, Tome of Battle, Tome of Magic
* Yes, I did find much of WOTC's material that disappointing.