I haven't opined on this yet, so here are my thoughts. (I know I'm late to the party.)
I think 4 top level headings would be good, no more - Video, Pinball, (Electro)Mechanical, & Chat About Anything. *MAYBE* a Marketplace at the top level. The front page seems very cluttered now. Scrolling is bad. Trees are good...if they're not too deep.
I *really* want the video and pinball stuff separated. That's important to me. I'm a vid guy and I don't care for the mixing. (And if I were a pin guy, or an EM specialist, I certainly wouldn't want to wade through all the video crap before seeing a nice relevant thread!)
For the subsections, I'd like to keep it simple. Something like what's below. I fleshed out the video section, but I leave the others to those with more experience there.
Video Game Forum
-- General Discussion
-- Technical Help and Repair
---- General Help
---- PCB/Electrical Repair
---- Cabinet Repair
---- Monitor Repair
-- Marketplace (move this to the top level and combine with pins, EMs, skills, etc?)
---- For Sale/Auction/Trade
---- Want to Buy/Trade
Pinball Forum
-- (etc)
Electro-Mechanical Forum
-- (etc)
General Marketplace (??)
-- Items For Sale/Auction/Trade
-- Items Wanted
That gives a 3-deep tree with only a few choices at each level. Not too bad for the slow readers like me. Or those with bad eyesight. Like anyone who's done too much tech work in their life.
I'm not entirely happy with it. I really like having Monitors as a separate section. And it would be nice to have cabinet topics separated from the electrical stuff. But then the list starts to get too long. And you still really need a General Help section. I do think you need to separate For Sale vs. Wanted in the Marketplace. But maybe Marketplace needs to be at the top level? Then it might be nice to combine all the machine types into one section...to grab more eyeballs == potential buyers/sellers. But still have separate FS/WTB sections. Clearly I need to think some more.
Tags could be useful, but I need to play with those to get a firmer grasp. I'm also playing with the idea of authoring a FAQ for using the Tech Help forum. That's a *big* maybe. (Only for how to get help -- not the repair FAQ itself!!)