11-13: chick pop (Cleopatra, B*Witched, Britney Spears)
12-16: alternative chick rock (Garbage, Tori Amos, Alanis Morissette)
14-16: electronica/dance/trance (Ferry Corsten, Puretone, ATB)
15-present: indie (The Wrens, Clinic, QoTSA before they got popular)
19-present: post-rock (Mogwai, Russian Circles, Holy Fuck)
Don't get me wrong, I'm still fond of the majority of the groups I used to love (Garbage, anyone?)--my tastes have just expanded with time. The years aren't entirely accurate; for example, I first discovered & enjoyed post-rock when I was 17ish, but I didn't really get into it until I was 19. There are other stages that are worthy of note: Brit Pop, Radio Pop, and 70s/80s Punk, among others. The above are what I currently consider to be the major influences in my life.
As a group of us went to Thousand Hills this afternoon, we heard Kill All Hippies by Primal Scream on the radio. My life is now complete. You got the money, I got the soul... can't be bought, can't be owned...