Pretty much since the beginning...
It was sometime in 2003, and I heard about it online in an anime chat room or forum board. Of course when I first heard about it, it was still just a manga. I started streaming subtitled episodes when there were only about 12 episodes made and they took forever, I think I was still using dial-up at the time. I remember after seeing that first episode I knew this was going to be something I would be following till the end.