All by myself ...

Here's a look at some lead singers whose solo careers soared:
Sting
The Police were almost as famous for hating each other as they were for their string of new wave pop hits (fused with reggae rhythms) like Roxanne, and Message in a Bottle. By the time they released Synchronicity in 1983, drummer Stewart Copeland, guitarist Andy Summers and bassist/lead singer Sting weren't even speaking to one another, which must have been awkward, since the album was their biggest yet, yielding unstoppable singles like Every Breath You Take, King of Pain and Wrapped Around Your Finger. Two years later, Sting had released an album called Dream of the Blue Turtles that made everyone assume that the Police would be back together before you could say "fake jazz." Well, that was 21 years, dozens of number one singles and countless zillions of dollars ago. Sting did move on and how!
Gwen Stefani
More recently, the fashion-plate lead singer of mellow punkers No Doubt broke free from that band's OC-meets-MTV style, which had birthed many an alternative hit (Just a Girl, Don't Speak, et al), and decided to "go for it" ("it" being the kind of mass appeal that plain old rock music simply can't get you anymore). The result of her efforts was the mega-platinum Love, Angel, Music, Baby, an album of catchy, genre-hopping pop confections like Hollaback Girl, What You Waiting For? and Cool, all of which were massive hits that left no doubt about the future of Stefani's musical pursuits.
Stevie Nicks
Burned out from the romantic, narcissistic and pharmaceutical indulgences of the band she'd helped resurrect, Fleetwood Mac, Stevie wrapped herself in innumerable shawls and struck out on her own for a series of albums, including Bella Donna and The Wild Heart, that were positively riddled with radio hits, including duets with Tom Petty (Stop Dragging My Heart Around) and Don Henley (Leather and Lace). Truth be told, her later albums were never as successful as those first two, and she always came back to the Mac. Still, her solo efforts sent a clear message to her soft rock comrades: She can and did go her own way.
Paul McCartney
Technically, McCartney wasn't the lead singer of the Beatles, but if you listen to their last few records (from Sgt Pepper through Let It Be), read the books and see the documentaries -- it becomes apparent that Paul was the driving force behind the band's difficult late period. George was frustrated, Ringo was busy acting in films and John was immersed in drugs and a budding love affair with Yoko Ono. They all knew it was over, but agreed not to say anything (and people always blamed Yoko!). McCartney sneaked off to Scotland and made McCartney, a brilliant collection of songs and song fragments, some for the ages (Maybe I'm Amazed, Every Night, Teddy Boy, Junk) and some for the dustbin (Kreen-Akrore, Hot as Sun). McCartney predictably went to number one, and has been followed by 35 years of blinding brilliance, utter folly and hit after mind-blowing hit.
Michael Jackson
It's hard enough to remember when Michael Jackson was a regular human being, let alone the adorable pint-sized lead singer of the Jackson 5. How many lifetimes (and how many noses) ago was it that the puny little kid with the voice like a rocket ship sang and danced his way into the hearts of billions around the world with evergreen gems like ABC, I'll Be There, and I Want You Back? Michael eventually got tired of carrying his brothers around on his narrow little shoulders and got the itch to do his own thing. With the help of genius producer Quincy Jones, he made Off the Wall, featuring Don't Stop 'til You Get Enough, and She's Out of My Life in 1979. It was brilliant. Four years later, Jones and Jackson came up with Thriller. The success of the album was so massive that it redefined the notion of pop megastardom. Everyone and their grandmother bought it. That was all well and good at the time, but it didn't do Michael himself any favours, since he obviously still lives in the fantasy -- 23 years, countless plastic surgeries and terrifying criminal proceedings later.