My introduction into RPGs was not D&D, it was the Dutch version of Das Swartze Auges (Oog Des Meesters), eventually we moved on to the Dutch version of the D&D Red Box, and from there to the English version of AD&D 2E. As far as I remember as a player we had very little official setting, if we had I never knew (or remember). When I started DMing I used my own setting with self made maps, I had the time for it and not the cash to invest in setting books (RPG material was rare and expensive at the time in the Netherlands).
My first real introduction to Dragonlance was the Champions of Krynn computer game, I never played/DMed the epic AP, I did read a few of the satellite novels. For me Dragonlance was always about Draconians and (evil) knights on Dragons, the Epic AP actually spoiled the setting a bit for me, the AP adventures I got my hands on didn't inspire me at all. I do think if a company like Paizo ever got it's mits on it, they could do a very inspiring AP path. I always wanted to use Draconians, but I don't think I ever did...
I did read a lot more FR novels, played some Eye of the Beholder and some of the later computer games. Sure Drizzt and Elminster were pretty powerful characters, but Drizzt was stuck in a hole in the ground in the FR equivalent of Alaska, and Elminster didn't go round saving every village and farmer. FR gave a lot more freedom as a setting then DL, but I still didn't use it as a setting until I got less time on my hands and a detailed ready to use setting became an asset. That was in the year(s) leading up to 3E and we started playing 3E before it was out (thanks to the 3E rumors on this site), I used Northern Journey as a basis and the extensive library of FR pdfs to make it a more sandbox campaign. I can spin a tale as good as the next DM, but creating a deep/large consistent background on the fly is difficult, FR as a generic setting helps a lot. Not to mention that settings like Al-Quadim, Maztica, and Kara-Tur intrigued me.
I never really got into GreyHawk because by the time that I did have money to spend on campaign settings, GH was on it's way out (and not readily available) and it's presentation never really got me motivated. I did like some of it's large maps and the idea of an demon kingdom...
I never did get into the 'big' changes 3E and 4E made to FR, I usually stuck to the 2E setting. I did buy the 3E setting books loyally and they are some of the most attractive setting books at the time. As I've mentioned before I never really liked the presentation of the 4E books the FR books weren't an exception.
I eventually did buy as much (2E) FR, DL and GH stuff as I could get my hands on without paying through the nose. But I think my favorite settings (I never got to play/DM in) are Planescape and Spelljammer. Birthright also got a special place in my heart due to the rules they introduced for running a realm (and the blood abilities associated).
I haven't touched a Forgotten Realms, Dragonlance, Battletech or Shadowrun novel in many, many years. While I enjoyed reading them at the time, they are the fantasy/scifi equivalent of sappy dime store romance novels, there are many good fantasy/scifi novels out there that don't try to fit into a RPG setting.
I think that Paizo is currently the best generic fantasy setting and their APs make for some very good specific campaign settings. But their not yet at the level of 'Volo's Guide to the North' (etc.) books were all kinds of interesting sites and inns are detailed, what is more important then an inn or an interesting site the party travels through...
If WotC does revive old settings for 5E, it would be wise to make the setting more era neutral, so players/DMs can actually choose when to play.