I've been posting covers and the original, and now a reader sent me this marvelous, long essay describing the song's remarkable journey through the music world. Money quote:
Jeff Buckley had to reach back to an artist of the 60s to touch the kind of consensus that "Hallelujah" has generated and maintained; nothing escaped the 90s similarly unscathed except Sleater-Kinney and Biggie. When we demand purity of our art, all art is inevitably impure, and possibilities are closed off; when we recognize the beauty of ambiguity, as in "Hallelujah," a universe opens up.
And the amazing thing about music criticism online is that you can listen to linked MP3s as you go along.