Which one's got a better voice?

Dev

http://www.youtube.com/watch?v=Cm0POLTxCLk

http://www.youtube.com/watch?v=jQTos6B-FwYfeature=related

or
Cassadee Pope

http://www.youtube.com/watch?v=KC4RSkm2vj0

http://www.youtube.com/watch?v=fXBC3Op0e3w

i hope you care enough to help me. im writing a story and i need to
imagine good voices for two characters in my story.