Without naming too many (Since it's quite a list), I'm gonna have to say:

Dave Gahan (Depeche Mode)
Martin Gore (Depeche Mode)
Wattie Buchan (The Exploited)
Sucker (Oxymoron)
Ola Klüft (The Perishers)
Jimi Hendrix
Billy Joel
Bryan Adams

That's a few to give you an idea.
I'd put myself in that list, but I'm a terrible vocalist.

Boy do I stand out like a steak between dairy products...

Sarah Brightman
Taylor Swift
Katherine Jenkins

Lacey Mosely (now Sturm) (Flyleaf)
Adele
Haley Willams (Paramore)
Sara Bareilles
Hillary Scott (Lady Antebellum)