I personally am an Otaku of a great many Anime/Manga and Musical forms out there. I get totally obsessed with whatever thing I may be watching/reading/listening to. I'm told its cos i'm a passionate person, which is mostly true.
I don't however start building shrines and things.. prolly cos I know my limits
I dunno why though. I remember the first thing I was obsessed with was Sonic The Hedgehog
I wanted to meet the creators of him and give them ideas and i'd write letters and get replies from Japan and stuff.. I even figured out how to record the Game Music from the games and remix it with songs and stuff.. all before I had a PC.
Ah.. the good old days