First song that comes to mind that you associate with D&D. Why?
The period of my life in which I was enjoying D&D the most also happened to be the period of my life in which I was going through my Zeppelin Phase, so that band as a whole tends to be connected with the game in my mind. In a similar vein, my discovery of the OSR coincided nicely with my discovery of The Sword; although I have a nostalgic connection between D&D and Zeppelin, I have to say that The Sword, writing explicitly fantasy-themed lyrics, nowadays forms a much more direct and literal connection with the game for me.
In particular, this track off their debut album never fails to make me want to sit down and start drawing dungeons...
And the slaying of the ancient wyrm
Would you dare meet the gaze of the basilisk
Or face the flames as the phoenix burns?