right now , I'm going to say
Romeo and Juliet - The Killers (Dire Straits cover)

Buckley's Hallelujah is the obvious one.

also:
Jeff Buckley - Corpus Christi Carol (i know it's not strictly a cover, but a version of a traditional song)
Johnny Cash - Personal Jesus
Manic Street Preachers - Umbrella
Keane - Goodbye Yellow Brick Road

is all I can think of for now.

__________________

seconded.
i preferred nirvana's version of the man who ruled the world.
and otis redding's a change is gonna come.
and god yeah, sinead o connor's nothing compares
on the johnny cash front, i'll go for hurt

__________________
anything is hard to find, when you will not open your eyes.

Emmylou Harris - The Boxer
Ryan Adams - Wonderwall
Johnny Cash - The Mercy Seat

__________________
I'm Squarepusher, and I approved this message.

Oh yea, The Mercy Seat. I like The Red Paintings' version of that. Not as much as the original, mind.
Also:
Nick Cave & friends - Death Is Not The End
המכשפות (feat. Nick Cave) - Shivers
Shane McGowan - Lucy (Version II)

__________________