Billboard.com reports the album from the 35-year-old singer, who was born Charlyn Marie Marshall, was tabbed as last year's best offering by many of Marshall's fellow musicians.
Among those allowed to cast their votes for the winner of the prestigious award were Ronnie Vannucci from the Killers, Wayne Coyne of the Flaming Lips and last year's winner Sufjan Stevens.
Stevens took home the award in 2006 when it was named the New Pantheon Award for his album "Illinois."
"The Greatest" opened on The Billboard 200 at No. 34 last year and as part of its Shortlist win, it will now gain a boost as part of an iTunes promotion.
The Web site said that by winning the music prize, the album managed to beat out offerings from artists like Band of Horses, Tom Waits and Regina Spektor.