What's your favourite cover version?

Please name the covering artist and the original where possible.
Some of my personal bests include:
Hurt - Johnny Cash (originally by Nine Inch Nails)
Baby One More Time - Travis (originally by Britney Spears)
Valerie - Amy Winehouse - (originally by The Zutons)

Stevie Wonder's marvelous cover of the Beatles "We can Work it Out. It's been a l-o-n-g time -but man- he added a "groove" that even the "Boys from Liverpool" Loved - really !!

Working Class Hero by Green Day (originally by John Lennon)

Rapture/Heart of Glass - Erasure (originally by Blondie)
Boys and Girls - Pet Shop Boys (originally by Blur)
Solsbury Hill - Erasure (originally by Peter Gabriel)

Wicked Game - HIM (Originally by Chris Isaak)
Message In A Bottle - 30 Seconds to Mars (Originally by The Police)
Bold As Love - John Mayer (Originally by Jimi Hendrix)

When The Levee Breaks - Led Zeppelin (Originally by Kansas City Joe and Memphis Minnie)

Although some people might disagree with me, I really liked Bon Jovi's version of Hallelujah, originally by Leonard Cohen.