What makes you fannish? And by that we mean, what is it about a tv show/movie/book/band/podcast/etc that takes you from, "Yeah, I like that," to "I need MOAR!!!" Is it a character? A plotline? The pretty? Subtext that’s just screaming to be acknowledged? In your own space, tell us what it is that gets you to cross that line into fandom.
The answer to this depends on whether there is any more. You can be as fannish as you like about something, but if no one else has heard of it and there's no fandom, there's not a lot to go on. And if there's a lot of official stuff, it feels like there's no need to go to fandom.
So Star Trek, for example, I love. I've seen all the TV episodes (including the animated series) and all the films. I take a day off work to go and see the latest film on the opening day. I read a lot of (Original Series & TNG) books, mainly in the 90s. I think, on the whole, that was enough. I wasn't there for the shipping, just the adventures, so that was everything I needed.
When I got into Doctor Who I decided it wasn't going to be like Star Trek and I wasn't going to get into the fandom either. I was trying to come up with an explanation, but the truth is that I don't know what happened there. Although, a lot of it was SJA fandom, rather than Doctor Who fandom.
Looking back, I think it ends up being the people, rather than the fan creations to consume/create or the even the original source materia. I met people through The Bill and Stargate and Doctor Who/SJA fandom. I'm still friends with some of those people. Those are the fandoms I had the most fun in.