Ashlee Simpson, October 23, 2004

The Performance: It was the jig heard ‘round the pop culture world. When a mistimed backing track exposed the prefab pop-punk princess as a lip-syncher during 'Autobiography,' Ashlee Simpson awkwardly stood on stage for a moment before doing a bizarre dance and running away. In the goodbyes at the end of the show, she tried to blame the whole thing on her band. “Didn't know what to do, so I thought I'd do a hoedown,” she said.

Career Impact: Although many a pundit -- and even the occasional former fan -- thought that the incident would single-handedly destroy her career, the Ashlee Simpson machine had a surprising amount of steam left in it. 'I Am Me,' her second album has sold almost a million copies to date. The first single, 'Boyfriend,' was a Top 20 hit while follow-up singles 'L.O.V.E' and 'Invisible' cracked the Top 40. She even got another chance at 'SNL' almost exactly two years later.