And I have done this twice in my life.:-)
But I think that the problem is that you need to be more specific in what you're looking for. Just folks to talk to, or a date or relationship, or just those who share your interests to interact with? DU meets most of those criterion, except for the personal relationship/date part. I came here for the politics, but have enjoyed the personal exchanges and just getting to know others who feel as I do.
Have you tried Yahoo? I know several DUers also post there. And you can choose a particular group there. But there is no protection against Freepers, which I assume you'd want to avoid...
http://groups.yahoo.com/I also joined a dog message board and IMDb, but I find that DU is all I really need. There's also FR, if you're looking for different exchanges, but you know I'm joking. But I belong there, too, and have posted there.:D
What do you hope to find that DU doesn't offer? With the groups, we really have become one-stop shopping, IMHO...:shrug: