At this time, PC is my favorite in terms of my comfort with the community and it's popularity. Other website forums I have visited may have been busy and helpful in the past, but are ghost towns now. A couple I left because of discomfort with a member (or more than one) that visited there. Occasionally I go back to them to see what's happening, but see they are becoming less and less popular.

One site I will mention is Reddit. It has a different feel and somewhat different "culture" than a typical mental health support forum, but that can be good sometimes. I am not familiar with all of their mental health related sub reddits. Only their r/BipolarReddit (which is best for bipolar support) or r/Bipolar (which is less support and more memes, jokes, and photos). On Reddit, there are some communities you can't find anywhere else. For example, r/MaladaptiveDreaming