Any vocals that you like?

Judy Collins--Who Knows Where the Time Goes (album)
Patsy Cline--Sweet Dreams
Joan Baez--I Dream of Jeannie/Danny Boy
Tom Waits--Blood Money (album)
Roy Orbison--Crying
Stevie Wonder--You and I
Aaron Neville--Save the Last Dance For Me

Patricia Barber "Too Rich For My Blood" nuf' said!

Beyonce' performing Etta James in "Cadillac Records" was pretty spectacular!

Off the top of my head and not yet mentioned:

Aretha Franklin
Joni Mitchell
Tina Turner
Eva Cassidy 
Annie Lennox
Nina Simone
Florence Welch
Janis Joplin
__________

Bob Dylan
Elvis
Al Green
Jeff Buckley
Jackie Wilson
Elvis Costello (Best terrible singer award)
Ray Charles
Curtis Mayfield
Smokey Robinson
Elton John
Robert Plant
Sam Cooke 
Otis Redding
James Brown
Marvin Gaye
(Younger) Van Morrison
Levon Helm
Simon & Garfunkel

people are different and some vocals one likes will hurt my ears such as:

Aretha Franklin,
Nina Simone,
Bob Dylan,
Same Cook...
 ________________

I really love Simon & Garfunkel "Parsley Rosemary and Thyme" album each and every song and recording quality too.