I'll take a crack at this.
Like a lot of teenagers I started with classic bands like Led Zeppelin and Nirvana but refused to listen to anything I deemed "corporate" or "pop".
From there I started getting real interested in hardcore punk (like what Btown said). Bad Brain's Rock for Light CD stayed in my player for months on end. I would cycle in between obsessions with Nirvana's In Utero (a very important album in my musical growth), The Smashing Pumpkin's Mellon Collie and the Bad Brains album. My interests grew more and more into punk rock and alternative rock.
I dropped the whole "pop sucks" attitude fairly quickly, when I came to the realization that Nirvana was essencially a pop group.
I had held a grudge against hip-hop for taking the spoit light away from Grunge in the 90's. The only stuff I had heard was today's radio stuff and couldn't figure out why people preferred this to rock music. Then through MB I learned about The Notorious B.I.G... did some research on him and instantly I was hooked. That got me into all the rap I enjoy today, plus Loathsome Pete's posts about Gruf the Druid got me into that great Canadian Underground stuff.
I had always loved classical and world music, and that love continues today.
Last year I discovered eclectic music blogs. It was all kinda new to me... I had always sorta thought you need to belong to some kind of musical social group or class (like punk, grunger, gangsta).
Part of the reason I like so much music today is because of the composers John Cage and John Zorn. Cage made me challenge what I thought of as music. Zorn made me realize that a genre can be so varied that it's rediculously close-minded to say you hate something because of the label it's under.
I now enjoy pretty much everything I hear (about 1 out of every 20 albums I get I feel I have to return or delete). A lot of who I am musically today is thanks to MB