Another great example where the cover turned out great is Maia Hirasawa's version of The Ark's song The Worrying Kind. In 2007 The Ark, with their energetic glam-rock competed with this song in the Swedish verison of the Eurovision Song Contest. In 2008 Maia performed this great cover and over night she got her breakthrough here in Sweden and went from independent singer-song writer to being at the top of the charts and "Maia" with the whole Swedish people. Watch both of the versions below.
Maia Hirasawa - The Worrying Kind 
The Ark - The Worrying Kind