Someone give me a idea for a forum/site i want to make a site but dunno what to make
If you make a forum on an idea someone suggests to you is it really going to go anywhere?? Don't make a forum for the sake of making a forum, make one on something you're interested in and know a lot about.
Yeah, for example, a few years ago, I was really into Nintendo Gaming. Thus I created Nintendo303. Then I got interested in Webmaster stuff so I went into Hosting, Designs, advertising, etc.
How about a website with forum topics for people like you? It will go places.
As Matt said.........If you don't know what kind of forum to create, you shouldn't be creating one!!