Run D.M.C. and Grandmaster Flash are often credited as the founding fathers of hip-hop. But when it comes to influencing modern rap culture, Big Daddy Kane, Slick Rick, and Biz Markie were undeniably da men. Take Markie, the human beatbox, whose off-kilter anthems like "Just a Friend" legitimized humor and wit in hip-hop. Or Big Daddy, who prophesied "Pimpin' Ain't Easy" before hustlin' was a twinkle in Jay-Z's eye. Think sex and materialism are new themes? Slick Rick pioneered them way back when, with his glistening bling and misogynistic rhymes. Yeah, rap owes a lot to these three sadly, each shrank from the limelight faster than you can say Yo! MTV Raps. However, they all have rabid cult followings, and for good reason: These oft-forgotten legends deliver potent and raw hip-hop the new school still strives to match.