I am not aware of when I first heard Hip Hop music, but I have been alive through its entire history. I have been fortunate enough to listen to many of the old greats and continue to kick it with the new wave of rappers and Hip Hop.
Recently I have been listening to a lot of old school Hip Hop on my long commute to and from work, and have been really loving the lyrical and thematic depth of these hard-hitting bangers.
(BTW, just in case you are not aware, Puerto Ricans invented Hip Hop along with African Americans. We were there from the very beginning in the Bronx and Spanish Harlem. we helped create Hip Hop culture - graffiti, break-dancing, MC'ing, and DJ'ing, all of it. Do not let anyone tell you otherwise.)
Public Enemy - Louder than a Bomb
KRS-One - Sound of da Police
Poor Righteous Teachers - Rock Dis Funky Joint
Gang Starr - Skillz
RUN DMC - Down with the King
Special Ed - I Got It Made
Eric B. & Rakim - Microphone Fiend
Public Enemy - Shut 'Em Down
Scarface - Never Seen a Man Cry
RUN DMC - Peter Piper