I suggest the groups Nightwish and Within Temptation.
But if I listen "D&D music" then my minds can't avoid to remember the song from the 80s cartoon.
Lyrics translation:
We arrived a fantastic world
full of strange beings.
The Dungeon Master
gave powers to all (us)
You the barbarian, you the archer
acrobat, wizard and the knight
Dragons and dungeons
an infernal world
hidden among the shadows
the evil forces.