Song help?!?!?!??

Hi can you tell me which ones are the 5 most powefull songs from this artists...(I say powerfull because I need powerfull songs to win a contest... also 1 being the most powerfull of the songs).... the artists are: Celine Dion, Mariah Carey, Leona Lewis, Alicia keys, and Kelly Clarkson..... please at least put three of the artists... and 5 most POWERFULL songs....