This is a very new forum site and I would like to suggest a few things that other forums have had and were popular threads.
A Media & Entertainment thread. This thread would consist of topics related to music, tv shows, movies, etc. People can also come here to show videos from their YouTube or just some clips they’ve made.
Sports thread. This thread would consist of all things related to sports. I’ve also always liked the idea of having a forum fantasy league for any sport.
GFX thread. This thread would consist of all things related to art, gfx, tutorials, etc. People can come here to show of their artwork.
News/Announcements thread. This thread will be the thread where forum admins will post anything about the forum and new additions.
I would highly consider adding these to the forum.