I got this idea from Facepunch (where I get [B]ALL[/B/] my good ideas). You need to structure the forum to where you need to click on the PC games subforum and it takes you to the list of threads. Here you can make any post about games. Then you have redirects at the top to the other specific types of games. This may sound slightly retarded so I'll show you.

General Discussion - Facepunch

Here you can see that this is the general discussion subforum and there is a redirect at the top to a more specific forum. This way people don't have to select a category at the start and are able to post general PC threads in less clicks and it would get viewed more by the people who never leave their subforum.