If I remember my path in (and there's probably some missing stuff here), excluding teen stuff like Pokemon/Digimon was:
Gundam Wing and Fullmetal Alchemist (in about 2005/6) with one of my younger brother, a bit later he gave me Fullmetal Panic! which I enjoyed but it still didn't peak my interest in the medium itself as a whole. He was BIG into anime and manga a few years back, he was into the whole cosplay etc scenes and everythin else at a point where I was just completely non-interested.
I also ended up watching Tekkaman Blade back in 2007-ish as one of my girlfriends, looking back, was quite into the area at the time (I seem to remember she had a thing for Cardcaptor Sakura).
Then back in ooh 2009-2010, I was given Deathnote and Elfen Lied by one of my best friends as he thought I'd enjoy them, shortly after I ended up meeting with Spice and Wolf, Kanon etc and I fell in love there.
Ironically my brother is now more 'normal' than he was back then in regards to his hobby, so as he's pulled out of the extremes, I've fallen into the fandom, which means we now chat on more or less the same level. This was part of the reason I enjoyed some of Oremo last year, as I could see parallels in my own past with my brother (obviously without any of the iffy connoitations haha)