The definitive version is Jeff Buckley's, the cool version is Leonard Cohen's, the 'to be avoided at all costs' versions are all the others!
I hated the fact that it was hi-jacked by the X Factor, and although I think Alexandra Burke has a good voice, she murdered it!
It's like 'Someone Like You' / 'I Will Always love You' / 'Your Song' etc., the song is so strong that it's almost impossible to make a lousy version of it, although quite a few have tried very very hard!!!!