Music has always been a mixture of the sacred and the profane, and Leonard Cohen's use of symbols and imagery in his poetic lyrics illustrate that perfectly. I'd have to say though, much as I love to hear the blessed Leonard sing his own work, the late, and much missed, Jeff Buckley's version of Hallelujah is, for me, the definitive version.
These days the split between the sacred and the profane in the music world is quite clear, pretty much all the singer/songwriter work is sacred and to be cherished, and the crap that spews forth from boy bands and the X-Factor, and the like, is profane. It is crass and it is hallow, and it is product. It is the musical equivalent of a sub-prime mortgage bundle. If you must have a copy of Hallelujah, make it Cohen's own, or Buckley's interpretation - or you will be contributing the the fall of mankind.
Jeff Buckley "playing and singing" Hallelujah.