My vote goes to GOT. Even in the off-season, content gets added every day. Supernatural's always been pretty active, as has TWD. I haven't spent that much time in the OUAT or TVD spots, but they seem to be pretty alive too.

Meanwhile, over in the spot for my current favorite... 7,000 fans and nobody but me has touched it in the last month. *grumble*

GOT or OUaT, I think. Compared to them, Supernatural's not as active. Idk about the other two.

As of now, anyway. Supernatural & TVD have died down in the past few years. Idk about GoT or TWD.

Oh, and another thing - GOT has a huge advantage, because it airs globally. I think TWD is shown quickly in a lot of other countries, too. Any international users wanna share how the other shows air where you are? Like, are they a week or a season behind the original US airing, or do you just watch them online? (File under: odd things that fascinate me.)

I remember when I joined the most alive spots were Grey's Anatomy, Glee, One Tree Hill, Gossip Girl and FRIENDS<333
Now they're all pretty much dead :(

+ GoT

I don't really spend a lot of time in the shows individual groups much these days, but from what I remember OUAT group was usually pretty active compared to many others

GOT and OUAT

Well. On my part it's TWD, because I keep adding stuff pretty much every day, and even I'm probably one of the more active on the spot, I'm still not the only one keeping it alive. Whenever there's a hiatus, I try to keep it alive as much as I can and I think I'm doing a pretty good job :)

^You are! =D