These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: The Ring of the Nibelung
Designated Hero: There are some people out there who cannot stand Siegfried, whom they view as a bully and a boor.
Wotan's pretty openly a Manipulative Bastard, the Rheinmaidens  taunt Alberich cruelly for their own amusement, Alberich is as miserable as he is power-hungry, and Siegmund and Sieglinde are incestuous murderers. Bruunhilde is arguably the only sympathetic protagonist, being manipulated rather than knowingly choosing evil, and accepting her Heroic Sacrifice to try to undo the crimes of everyone else.
Epic Riff: "The RIDE o' th' VAAALK'-ries, RIDE o' th' VAAALK'-ries, RIDE o' th' VAAAAAAAALK'-ries, RIDE o' th' VAAALK'-ries."
Or: "Kill da wabbit, kill da wabbit, kill da waabit!"
Harsher in Hindsight: Wotan punishes Brunnhilde for disobedience by stripping her of her power and reducing her to the status of a lowly wife. In Wagner's time, this would have been the standard role for a woman and would possibly have been seen as an Ironic Hell; however, in today's more emancipated world, many women can easily empathize with Brunnhilde's horror at the prospect.
Memetic Mutation: The expression "It ain't over till the fat lady sings" is very possibly a reference to the end of the Ringnote although an even better case can be made for Tristan, which actually ends with Isolde's Liebestod. The last scene of Götterdämmerung, features Brünnhilde singing a exceedingly long farewell to the dead Siegfried („Starke Scheite schichtet mir dort!note "Stout timbers stack for me there!"), although the very last vocal utterance of the work is Hagen's „Zurück vom Ring!"note "[Keep] back from the Ring!".
Newer Than They Think: Wagner's depiction of the three Rhine-daughters is largely a creation of his own imagination; though wise-women appear in the Danube in the 12th century Nibelungenlied, there is no indication that they are native to it, much less the daughters of its personified god, and they never go near the Rhine at all.
Seinfeld Is Unfunny: Wagner's „Musik der Zukunft" ("The Music of the Future") was considered daringly, even outrageously, innovative in his own time; but he became so influential that his music is now reckoned old-fashioned and even stereotypical by some.