Ashlee Simpson
In 2004, Ashlee Simpson graced SNL with perhaps the most famous Irish Jig in television history. The pop starlet broke into the awkward dance after a tape of her song “Pieces of Me” – complete with vocals – began playing over the intro to her second song, revealing that her earlier performance had been lip-synced.
Simpson first blamed her band, then a case of acid reflux for the error, but the damage was done to her reputation. She returned to SNL in 2005 but hasn’t been back since.