little of both. When I was younger and totally certain that I posessed an almost unfair amount of sheer awesomeness, I was also certain I was going to be a horror writer.....part because I read horror mostly, and part because the only thing I had more of in me than awesomeness was sheer badassery. (oh yeah, and humility).
Now I write what interests me, and mostly that seems to be people trying to become more than the fuckups they are, and either succeeding or failing and dragging everyone within reach down with them. Now some of that is actually framed within horror, some thriller, and some, God help me, mainstream love story even. I'm finding I write what comes to me, and it usually starts as a theme and then sprouts enough plot to find a genre.