Tom Service writes in today's Guardian,
...there’s no more arresting opening or ending to any operatic drama than the start of Das Rheingold or the climax of Götterdämmerung. And the 15 hours in between aren’t bad either.Probably not a good starting point then, unless you're really into pompous music, epically long storylines, and always carry with you a well hidden worn-out copy of the Lord of the Rings. The story plunges straight into the mythical landscapes of the Nibelugenlied, written around 1200 AD, whose legends permeate the German psyche the way the stories unfolding in the Iliad stir the Greeks.
Without further ado, here's a powerful piece from the last part of Wagner's Ring cycle, Götterdämmerung.
"Sigfried's Death and Funeral March".