Rihanna -- Please Stop the Music!
There's a reason the judges on "American Idol" tell contestants to steer clear of Mariah, Whitney and Celine -- no matter who you are, it's near impossible to measure up. Rihanna is not the exception.
In this video from an old high school talent show, RiRi tries to tackle "Hero," and though she starts out fairly strong, the song completely falls apart at the end. Not that Mimi's perfect either -- watching this is still easier than trying to sit through "Glitter."