I came to Dragonlance through a marriage of convenience. I was at uni, looking to DM something new, and my flat-mate offered to sell me his DLCS and a couple of the starter adventures so he could buy the Epic WH40K starter set he wanted. Since I *also* wanted to play the new 40K hotness, this sounded like a good deal. Afterwards I took a trip to the local Virgin Megastore, only to find they had the entire DL series on sale (yes, there was a time when Virgin Megastores sold RPG stuff!). So within 24 hours, I was completely campaign-ready.
As it happened, the university group fizzled, but my home group was very keen to start something long-term as a kind of statement that we wouldn't let our imminent adult lives wreck our gaming. I offered them Dragonlance, and the rest is history. On and off, we played that campaign and offshoots from it for more than twenty years.
Much of the value it holds for me is therefore wrapped up in keeping the band together. We've joked about its flaws over the years, they as players and I as DM (many of the modules are a nightmare to run, let's be honest), but what that original campaign achieved, and the innovations it brought to the D&D landscape, are second-to-none. The DLCS hardback is a beautiful book; in no way is it enough to run a decent campaign, but it is beautiful, nonetheless. The myths and history of the setting are rich and easily brought to bear in any game. It has kender and tinker gnomes, two of the most insane races in D&D history, and yet responsible for the most memorable PC's I've ever DM'd. It took hundreds and hundreds of hours of my life to make it work, but our Dragonlance campaign still stands as the yardstick by which all others are measured.
Later I had the privilege of working with [MENTION=3867]Dragonhelm[/MENTION], Cam Banks and many others much more talented than myself on the 3rd Edition version of the game, and those books with my name in have a very special place on the shelf as well. These days, my local group is more FR than Krynn, but my old home group still gets together every month or two, and one of the games we play is a Dragonlance 5E home-brew. I'm pretty sure we'll be playing a version of that campaign world pretty as long as we have breath in our lungs.
P.S. Love the idea of positive-only threads!