Surprisingly haven't found a whole lot on this. I suppose most people scroll through their systems one after another, but I like the idea of having a separate system menu that branches out to the rest, and I have seen examples of this when googling around, though the examples never led to a download link.
Right now I'm using Game Station HD (especially for the useful file info it brings up) and Nevato (modded to straighten the wheel and give more real estate to the background) for MAME, and probably plan to use Cosmo's various robospin-like themes (again, possibly killing the angled aspect of the wheels). So that's sort of the look I'm after. Vertical wheel on one side, system info with a video and other art taking up the rest. Probably most themes follow that structure, come to think of it.
