I mostly lurk on DS now... I only reply to threads that ask a question, or if I give my opinion on something without expecting a reply.
All the private jokes and casual conversations in the threads make me cringe! I remember trying to contribute once, but got ignored.
I hate the Strictly spoiler thread where they talk about random stuff whilst they're waiting for the spoiler.
Some of them seem to go into hysterics about inane things, such as eating a family sized bar of Cadbury's to themselves.
There is another forum called Walford Web, which is an EastEnders forum. Wow, that is even more cliquey than DS or Mumsnet. All my posts get ignored or shot down. I've noticed there is only a couple of other posters who will interact with me/'like' my posts. I mostly lurk on there now, too.....