I listen to alt, indy, and basically whatever sounds good... I don't discriminate. A small cross-section of alternative and alternrock I have includes:
This is Fort Apache,
The Beat(En) Generation Volume 1, Local H, Garbage, Filter, Lowest of the Low, Matthew Good, Modest Mouse, The New Pornographers, Stars (my fave), The Weakerthans, Travis, Sloan, Moseley Shoals, etc. You get the point.

As for clothing style, I don't know, I still have to define it! As a guy I dressed more alt than anyone in my peer group; girls thought I looked cool, guys thought I looked gay (so did my parents, and they made sure I knew they knew). hahaha