I grew up listening to my dad's albums. (My mom didn't have very many of her own.) My favorites were his Bill Cosby comedy albums, a double-live Peter Paul and Mary album (that I still need to buy on CD) and Harry Belafonte (which he also loved to sing when he was in the bathtub).
My mom listened to an AM radio station that played oldies, so I gained an early love of 50s and 60s stuff.
My youngest aunt was where I discovered rock music. She had Led Zeppelin (the one with "Stairway to Heaven") and The Beatles "Abbey Road," along with other not-so-cool discs like Andy Gibb and John Denver.
The same aunt bought me my first album for Christmas in 1980: a K-Tel collection called "Rock 80." It was SO AWESOME. It had Pat Benatar, Blondie, Cheap Trick, and "Pop Muzik" by M.
The first albums I bought on my own were Men At Work's "Business As Usual" and Huey Lewis and the News' "Sports" ... and a story-record of "Return of the Jedi."
My cousins lived in a bigger city than I did, so when they came to visit, they exposed me to stuff I hadn't heard yet as a teenager: The Cure, Depeche Mode, REM and U2.
We didn't have cable, and even though my conservative parents expressly forbade me from watching MTV, I watched it at my grandma's and my best friend's, so my musical knowledge expanded quite a bit as a teenager in the 80s.