Be aware that the Dark Elf Trilogy of Drizzt's origins in the underdark and coming to the surface were a prequel trilogy written after the Icewind Dale trilogy which were the first novels Salvatore wrote. The characterization for Drizzt in those first ones is a bit different from later characterizations (more of a cold killer in the original surface trilogy whose good is mostly that he fights evil, less of the clearly moral hero he becomes in later characterization in the Dark Elf Trilogy and later written stuff). If you start with the Dark Elf trilogy and follow it up with Icewind it could be a little jarring.
In the Dragonlance line my favorite was Weasel's Luck by Michael Williams, a fairly standalone novel set before the main Dragonlance trilogy. I also really enjoyed the Hickman and Weiss short story anthologies in Dragonlance Tales. The Medusa's Eye series I remember being decent as well.
In Greyhawk I read the original (1e era) Wolf Barbarian stuff by Rose Estes, I liked the author's Endless Quest books much more. I heard good things about Paul Kidd's WotC era Greyhawk novels but have not read any. Gygax's official Greyhawk ones which lead into the not TSR Gord the Rogue series are OK, it has parts I really enjoy but I really dislike some elements and the series anitclimax ending.
I read most all of the original Ravenloft series of novels, the first one Vampire of the Mists by Christie Golden was my favorite. Some rave about Knight of the Black Rose, but I preferred his characterization in the original Dragonlance series by different authors more, so for me it was overall good but not my top.
