14-year-old me had a different perspective of the world and literature than me writing about this today. So while I don't think I would enjoy half the books I read as an adolescent in the 80s, I can remember fondly how these books excited and fueled my imagination.
The first true D&D novels I read were Saga of Old City and Artifact of Evil, the first two books in the Gord the Rogue series by Gygax. Gord was the reason I had such a strong affinity for rogue characters with dual-daggers. (Eat it, Drizzt!) Plus, the books included some beautiful black and white illustrations by one of the iconic artists for the game, Clyde Caldwell.
Of course, the original Dragonlance trilogy was a staple for every D&D fan at the time. More than a great story, it was a blueprint for world building on a level that most of use only dreamed for a campaign setting. It was also how I imagined a great adventure campaign should be; a continuous, evolving story with strong character motives, and a definitive ending that could only be achieved through great struggle and sacrifice. Those were pretty lofty goals at a time when most campaigns were often built on a string of adventure modules that weren't always connected.
Finally, I think the Cleric Quintent series by Salvatore needs more attention. It didn't spawn a slew of spin-offs and endless trilogies like the drow. I don't even remember most of the plot. But what I did get from it is this: even a dull or boring character concept, like a human cleric of Denier (the FR god of literature, art, and knowledge), can be an interesting and compelling character to play. The character makes the character interesting: not the race, or class, or whatever.