I'm surprised no one has mentioned the queen of covers.
After leaving Ike and before her great comeback with the Private Dancer LP, Tina did not have the luxuary of being handed great original songs but she liked to cover songs she loved, which she did not give up even afterwards.
Here is a New Year special - all songs are great covers except the last one Nutbush, which she had penned herself.
Johnny Cash singing "The Mercy Seat" on American Recordings III. I love Nick Cave's original, but Johnny brings his "voice of God" presence to this spinning demon of a song. Pretty intense!
Carpenters' Ticket to Ride
Sergio Mendez and Brazil '66's Fool on the Hill
Bruce Hornsby's Madman Across the Water (by a whisker)
All products of master (re)arrangers.
Honorable Mentions: Three Dog Night's Eli's Coming, Blood, Sweat and Tears' God Bless the Child, Patti Smith's Raindrops Keep Fallin' On My Head (gotcha!)