DaveS,
       I also love the Jeff Buckley version of "Hallelujah". My wife and I had a friendly disagreement over Jeff Buckley vs. Rufus Wainwright going until we found the one by these four Norwegian guys.
It's just these four guys sitting around a studio with simple acoustic guitar accompaniment by one of the four, but they all have excellent and unique voices. They each take one verse and sound great but when they combine harmony on the chorus it is divine.