>>17
Avatar SERIES. The trilogy is nothing without Prince of Lies and Crucible: The Trial of Cyric the Mad to wrap things up. Besides, Prince of Lies is the story of the Cyrinishad, and thusly the most amazing and insightful of all of the books, as well as cleverly written with an unreliable narrarator. Easily my favourite Forgotten Realms books.
Beyond those, The Dark Elf trilogy was okay, the Icewind Dale Trilogy is an overhyped piece of shit. It's very uninspired and bland. Cormyr, and pretty much anything by Ed Greenwood is nice. Typically, the newer books suck, though I've heard some good things about the "The Fighters" series.
Also, avoid the Baldur's Gate books like the plague. God damn...