A song murdered by someone.

The original version of "Unchained Melody" is so superior that the Righteous Brothers cover shouldn't be played? 

Only the Righteous Brother's version should be played. All hyperbole aside....I think it is the best and others fall short. But its music. People like what they like.

Larry, in general I too dislike operatic covers of popular songs, and like you I don't think I've listened to the couple of Dame Kiri's crossover albums I have more than once or twice. 

There are exceptions, though.  One that I'd particularly recommend would be a 1985 album by Julia Migenes (then known as Julia Migenes-Johnson) entitled "In Love," in which she wonderfully performs a dozen or so classic Broadway show tunes.  Of course, it's not entirely coincidental that in addition to opera she has a substantial background in the theatre.

Speaking of Dame Kiri, one of the most fantastic concerts I've been to was a recital of purely classical material that she gave in New Haven, Connecticut, about three decades ago.  When she was in her element she was certainly a very special talent.

Best regards,
-- Al 

Also I have a cover that I do not like at all and in my opinion has lost all, and I say all the poetry and melancholy of the original version, it seems that the band took the music and the words without bothering or wondering what it meant and the 'have adapted to their style and the result is, for me, bad, unacceptable, I realize that the band has many fans and they will disagree and even think that everything has been improved, no, it is not so.
I'm talking about "Knocking on hevens door" by Bob Dylan in the cover of guns & roses that have also done very nice things but not in this case.

I've heard so many people and some critics rave about that GnR song. It is probably my least favorite thing they ever did.