Rebecca Black, "Friday"
Rebecca Black, 13, wanted to be a singer when she grew up. So her mother forked over $4,000 to production company Ark Music Factory to create a vanity music video for her. What was supposed to be a fun project ended up propelling Black, now the ripe old age of 14, to viral stardom. The song's lyrical platitudes ("Yesterday was Thursday, Thursday / Today it is Friday, Friday") and relentlessly catchy chorus led to the video racking up millions of views — and becoming YouTube's most "disliked" video ever, surpassing Justin Bieber's "Baby." Since "Friday," Black has released two more singles, though neither has the novelty appeal of her first go around. But Black needn't fret — at least once a week, her song is guaranteed to get stuck in our heads.