I am looking for a niche on which people want forums. Which forum do you want now? what things you looking for in a forum? there are many webmaster forums, many dating forums, which one are we missing?
Hy, Do you remember Seinfeld? They said that they made a serial about nothing. I don't know how a forum about nothing look like, but their movie was successful. Maybe it gives you an ideea.
I would go with techhy forums, as there are lot of tech forums, but still I feel some latest stuffs are always kept behind to discuss.
Random Topic forum might be cool. And make sure it is a do-follow one. Aside from that, people also may look for a relationship forums that discuss everything about feelings and emotions, next are webmaster forums like this that discuss trends about SEO.
Do you have any suggestions that you would like to share with us? After all you are making a forum for us...
Start a forum of anything that is IN these days, technology, updates anything that catches the eye. And give something to the members. That will make you real popular.