2nd Edition: Dragonlance

It's almost redundant to say that Dragonlance was both a megahit that rejuvenated TSR, and a point where Dungeons & Dragons made a turn away from it's previous tropes. Unlike modules like Keep on the Borderlands or Tomb of Horrors, the story was the focus of Dragonlance. Notably, this was around the time Bothered about Dungons and Dragons was putting pressure on TSR, and Dragonlance offered a setting that got away from the amoral gathering of treasure, the slaughtering of monsters, and the references to demons and devils. This asthetic would find their way into 2nd edtion as well. I'm not saying that Dragonlance was created in response to the criticisms against D&D, but it certainly was a convenient world for TSR to distance itself from those criticisms.

Unfortunatley, the original Dragonlance modules also removed a lot of the open ended gameplay. DL1 was certainly not a terrible module, but it was very linear. On re-reading my copy, I noted the use of the march of the Draconian army as a tool to herd the players to the ruins of Xak Tsaroth, and a pretty heavy hand in the resolution of the combat with the dragon Khisanth.

I lost interest in the Dragonlance modules after D3, Dragons of Hope. All the Dragonlance modules up to that point were pretty much similar in structure and play. There's a few interesting ideas, like the use of discrete events along with locations, or the politics of the refugee caravan, but these ideas, to me, were not fleshed out or used as well as they could have been. 

And then the novels came out. It was clear to me, even then, that Dragonlance was a much better series of novels than a series of modules. Later on, Dragonlance would get setting books that didn't tie into an overarching plot, and so become much more palatable as a game world. I think it's fair to say that Dragonlance was a kind of precursor to the settings that would come during 2nd Edition.