well, you can use VG$ in the prediction league or for FAQs (punch-out!! has a lot, and it's cool because I get to see when people buy my hints
)
Other than that, it is a way to see who contributes to the website. People with lots of VG$ probably work in the database, and probably know a lot about a lot of games. You could probably ask me about any DS game and I've probably heard of it to some extent
(should I be proud of that??)
As for fun things to do, mostly read news/threads, work in the game database, or play in the prediction league. Since you've been lurking for so long I'm assuming you know where most of the charting tools are located so there probably isn't too much to discover.