Best YouTube Video: Susan Boyle
She was the unexpected songstress that took the world by storm. Thanks to YouTube, this Britain's Got Talent contestant's vocals weren't limited to the UK. Even judge Simon Cowell admits he didn't take her seriously when she showed up for her audition. But as soon as they heard the first note of "I Dreamed a Dream," the judges were raptured. So were we. Since the legendary audition, the video got more than 1 million hits and Susan Boyle—who didn't win the season—released an album that hit number one before it even hit stores. No audition required.