If it is about the forum itself or the website, then it belongs in this forum, rather than either game suggestion forum. Even if the topic is not directly about the website (say, about graphics programs or web hosts for avatars), then it would fit better here than any of the game specific forums. Of course it it is unrelated to either the site or games, it goes in one of the chat forums.
There have been topics with miscellaneous suggestions here before, but the default view of the 'About this website' forum is to show only topics from the last month in the index, so you would need to either change that (this option is shown near the bottom left of the index page) or search the forum in order to find them.
