Back in the day, way back in the day perhaps, there were interesting places to hang out online. FidoNet provided some discussion groups — some local, some more national or international. Then there was Usenet, with the same but on a more grand scale.
There were things I liked about both of them.
They fostered long-form, and long-term, discussion. Replies could be thoughtful, and a person could think about it for a day before replying.
Socially, you would actually get to know the people in the communities you participated in. There would be regulars, and on FidoNet at least, you might bump into them in different groups or even in real life. There was a sense of community. Moreover, there was a slight barrier to entry and that was, perhaps, a good thing; there were quite a lot of really interesting people and not so many people that just wanted answers to homework questions.
Technologically, you got to bring your own client. They were also decentralized, without any one single point of failure, and could be downloaded and used offline. You needed very little in terms of Internet connection.
They both had some downsides; Usenet, in particular, often lacked effective moderation. Not everyone wrote thoughtful posts.
Is there anything like it these days? I’ve sometimes heard people suggest Reddit. It shares some of those aspects, and even has some clients capable of offline operation. However, what it doesn’t really have is long-form discussion. I often find that if I am 6 hours late to a thread, nobody will bother to read my reply because it’s off their radar already. This happens so often that I rarely bother to participate anymore; I am not going to sit at reddit hitting refresh all day long.
There are a few web forums, but they suffer from all sorts of myriad problems; no cohesive community, the “hot topic” vanishing issue of Reddit, the single point of failure, etc.
For awhile, Google+ looked like it might head this way. But I don’t think it really has. I still feel as if there is a vacuum out there.