mythusmage said:
What matters is not what you use, what matters is how well you use it.
I agree. That's what matters, really. There are several ways to present "recycled" materials at the game table the players would be likely to recognize.
First, you can alter said material so that it becomes unrecognizable by the players but still fuels the game by providing adventure arcs, characters and such.
Second, you can present it in such a way that the players do recognize it, but more as an homage or private joke than anything else. This can work with some players, yet won't for some others (particularly those with a low threshold of disbelief).
There is such a thing as too much of a good thing, however. Originality of ideas/game elements on the DM's part helps keep a game fresh and engaging to the players. They are exploring locations, dealing with situations never encountered before - that, in itself, is an element of interest for some people playing the game. Lots of gamers want to accomplish something through their character worthy of rememberance like the travels of the Fellowship of the Ring. Few will want to replay the whole thing step by step, however, because it's not "new" to them, first, and because they aren't really "the ones" accomplishing the feat of adventuring: the tale's been told before.
One thing that counterbalances this take on adventuring is the "shared experience" role-playing games, and D&D in particular, provide. Every fan of D&D wants to play the Temple of Elemental Evil or White Plume Mountain or Expedition to the Barrier Peaks at least once to be able to know what it feels like. That seems to me to be a huge part of the passion for D&D, and this entails that D&D adventures have to share something in common that makes the fan of the game think "alright, this feels and tastes like D&D".
Of course, the way these elements influence a particular D&D gamer vary greatly from one individual to another, but generally, they're present and are part of the "D&D experience", so to speak.