It used to be that very few stars went by a single name. Madonna started her career as simply Madonna (and good thing too; having to say Madonna Louise Ciccone every time we talked about her would be a mouthful). But over time, and with the advent of more and more gossip magazines and blogs, features like, "Stars -- They're Just Like Us!" -- stars have increasingly become referred to on a first name basis. We've singled out the biggies, starting with ...

Cher
Cher had her last name officially dropped in 1979; in some ways, it was a mere formality: she had been known to most of the general public as Cher since the show 'Sonny and Cher'; and her two given last names, LaPierre and Sarkisan, weren't as simple as Bono. So when she divorced Sonny, it seemed easier to go with Cher.