I think my parents win the youngster award, as they are both in their early 50s.
Both are professional folk musicians (ever hear of Wickford Express?), so all three of their children were exposed to all kinds of stuff. Around the house we heard a lot of Bob Dylan, etc. songs from my father, but it was their professional repertoire that shaped all of our lives: traditional maritime music.
I can't say I have a favorite, but I know every song they ever sang, and plenty more that I found on my own in the same genre. It sure has been great, growing up with people like Stan Hugill, Louis Killen, Dick Holdstock and Alan MacLeod, Johnny Collins and Jim Magean, Jeff Warner and Jeff Davis, Stuart Frank, etc. popping in and out of our living room. (I hope that didn't sound like name-dropping; just listing people I've been particularly influenced by.) My mother visited the Glenns a few times in North Carolina and brought back some goodies...But everything we know has been documented already, and we got it from the documentation.
I don't think any of my grandparents sang; they are the kind of people who grew up speaking Canadian French but refused to teach it to their American children. My great-grandfather used to sing to my father, but he was so young he doesn't remember any specifics, just the fiddle playing.
I have to say, though, that my happiest memories are of my father singing to me at bedtime. I plan to continue that tradition with my own children. Traditional music is the most wonderful gift to pass on in this modern, wasteful, forgetful culture.