a couple here....
Word Up...
Cameo (original)
http://www.youtube.com/watch?v=w39Z5nmFmqo
Gun (seriously rocked up cover)
http://www.youtube.com/watch?v=uufUktrTCTg
Downtown Train
Tom Waits (another singer who challenges Dylan for not being able to sing)
http://www.youtube.com/watch?v=bzfCu3pvE1A
Rod Stewart
http://www.youtube.com/watch?v=3ffj6hKN2n0
You Can't Hurry Love
The Supremes
http://www.youtube.com/watch?v=2ZVRwHrCTp8
Phil Collins
http://www.youtube.com/watch?v=dYC5E4perb8
The Phil Collins version may be the closest to a true cover ever recorded. He was very insistent in copying the exact sounds of the instruments down to the sounds of the drums so that the vocal is the only different part. Apparently, the drum skins had to be so loose as to almost fall off to duplicate the original sound.
River Deep, Mountain High
Tina & Ike Turner
http://www.youtube.com/watch?v=ULw1RHHPv5g
Jimmy Barnes (typical Barnes highly rocked-up version)
http://www.youtube.com/watch?v=R39Z7QrnyiA
Sweet Soul Music
Sam Cooke (original unfinished, unreleased at the time version called "Yeah Man")
http://www.youtube.com/watch?v=C9hjmLPq6Zw
Arthur Conley (re-written into the familiar song after Cooke's death)
http://www.youtube.com/watch?v=hE61gCVht4Y
Shake Rattle & Roll
Big Joe Turner (original, rarely heard version)
http://www.youtube.com/watch?v=20Feq_Nt3nM
Bill Haley (VERY sanitized lyrical version)
http://www.youtube.com/watch?v=MpT8Sd9wRlQ
Gimme Some Lovin
Spencer Davis Group
http://www.youtube.com/watch?v=f4Wvxg-hV-0
Thunder (live version from the great, sadly recently-disbanded UK hard rock band)
http://www.youtube.com/watch?v=KU2AzdaqQ1Y