Hurt by Johnny Cash immediately comes to mind.
There are two types of people in this world. Those who think Johnny Cash's version of Hurt is better than Nine Inch Nails' and those who deserve to be round up and shot.
Ok, a little extreme but the NIN version is way better.
Nirvana- Man Who Sold The World (David Bowie Cover)
Iron and Wine- Such Great Heights (Postal Service Cover)
Sonic Youth- Superstar (Carpenters Cover)
Nirvana- Lake of Fire (Meat Puppets Cover)
OK, this was going to be my post. Especially Lake of fire and man who sold the world (Even though Bowies version is great too).
Except that I do like Johnny Cashes version of Hurt just about as much as NINs. They have diffrent merits.
One is that of an angry young man looking into his frightfully short looking future and the mistakes of his relatively young past, the other carries all the heavyness of a long life full of regrets that is going to end soon. It's like two sides of the same coin and they're both beautiful.
Also Lana del rey - The other woman.