Artist: Taylor Swift
Who She Dissed: One Direction's Harry Styles
How She Dissed Him: Even pop stars know how to throw shade! During the opening performance of the Grammy Awards this year, Ms. Swift ended her live show by speaking in a British accent and mocking her ex-boyfriend. "So, he calls me up and he's like, 'I still love you,'" she said, "and I'm like, 'I'm sorry, I'm busy opening up the Grammys and we're never getting back together. Like, ever.'" Burned!