15. Joey Bada$$: 21 Under 21 (2013)

Josh Wehle

Joey Bada$$

Last Year's Rank: N/A

Birthdate: January 20, 1995 (Age 18)

Why He's Hot: Joey Bada$$ turned heads in 2013 when the Broooklyn rapper released his critically acclaimed debut mixtape, "1999." Him and his crew, Pro Era, have breathed a fresh of breath air to New York. He's released two mixtapes since "1999" -- "Rejex" and "Summer Knights" -- and is currently working on his debut independent studio album, "B4.Da.$$," due  early 2014. On his 18th birthday, Bada$$ was named creative director of Echo Unltd.