I've been a member of Large Penis Support Group since back when you had to write your username on it, before we found out the girl who ran it was collecting them like Pokemon, but I don't know if they have a horror movie section.
I don't think, therefore I am not.

Bluray.com has a lot of traffic and discussions remain quite active. The only problem is that you can't organize discussions through individual topics as you can here, and the process of wading through hundreds (or sometimes thousands of posts) all grouped under one movie can be quite tedious. Also, the site is geared toward videophiles so it can get quite technical at times.
Reddit probably has even more active users than IMDb but suffers from the same problem.

Another point: On HMF, we also have October horror movie challenges, for anyone wondering.

Just joined Trash Epics and Upcoming Horror Movies.

I've been a long-time member of Horror Movie Fans. It's a small community at the moment (due to the fact that our original website had hosting problems), but it might be worth looking into as a supplemental choice.
http://hmfspareboard.proboards.com/
By the way, this is such a terrible decision on the part of IMDb. How are we supposed to discuss and dissect obscure horror films without a board to do such on?
Anyhow, if anyone wants to join, we'd be happy to have you. Fun fact: Horror Movie Fans formed as a forum after having meant each other on the horror boards right here. This happened over ten years ago, so though this move is idiotic, I'm sure that many forums will pop up and be ready for all of us horror fans to migrate to.

a couple of horse racing ones that's about it.

Well, Frank. Looks like another one of those long, hard ones William Kerwin

Or staying on FB. Losers.
I collect dead pigeons then I press them between the pages of a book.

Looks like everyone's going over here.
http://trashepics.com/
Well, Frank. Looks like another one of those long, hard ones William Kerwin