I only run published adventures very rarely out of the box. I have run a few – T1 The Village of Hommlet comes to mind – straight as published, but on the whole I look at adventures more as mini-sourcebooks about a facet of the game world (in my instance, Greyhawk, of course), rather than for their adventuring potential in and of itself. I assume this places me in the minority when it comes to consumers of D&D adventures.
This, in large part, explains my fondness for location-based adventures over plot-based adventures.
Even adventures like A1-4 (the “Slavers” series) fall into this category, although I understand they are favorites of Greyhawk fans from way back. I find that I enjoy them more for the information they contain about Highport (A1 Slave Pits of the Undercity), the humanoid stockade in the Drachensgrab Hills (A2 Secret of the Slavers Stockade), the town of Suderham (A3 Assault on the Aerie of the Slave Lords / A4 In the Dungeons of the Slave Lords), and the general idea and information about the Slave Lords, than for the specific plot that the PCs are expected to be following.
The same goes for a module like S4 The Lost Caverns of Tsojcanth. When it first came out, I was infinitely more excited by the new monsters and magic items (which were eventually incorporated into Unearthed Arcana and Monster Manual II) than I was by the adventure itself. But even there, it’s the background concerning Iggwilv and her conquest of Perrenland, the political situation between Perrenland, Bissel, and Ket, the NPCs included, and so forth that I find most interesting.
Even the most plot-driven adventures have information that enrich the setting even outside of the plot itself. NPCs, locations, magic items, and even the events of the plot themselves (used as background, as things that either happened in the past or are happening in the background while the PCs are in the vicinity) can be extracted from such adventures.