Like, when I heard "Ladies and Gentlemen -- the legendary Britney Spears!"????

Well, maybe -- someone who causes legends to happen when they're still alive:

The legendary William Shatner.
The legendary Monica Lewinsky.
The legendary Justin Timberlake.
The legendary Tom De Lay.
The legendary Don King.
The legendary Hanson.
The legendary Celine Dion.
The legendary Charles Manson.