Dragonlance kept me from abandoning D&D in the 80's. I was getting tired of the mindless dungeon-crawling, and the story-based approach made me realize there was a whole aspect of D&D I was previously unaware of. (Though I have to agree, attempting to run the actual DL module series is unappetizing - as would attempting to recreate a campaign doing the same exact Lord of the Rings as the books. But the ideas and general storyline are great!)
And hands down, Ravenloft is my favorite adventure of all time.
I wouldn't put Hickman as a founder, but definately an architect and an influencer.