I just started this new project and I think I might have a great set up for a game console.
The plan here is the original build without the cartridge will be relatively simple. All the game events will be put into the cartridge insert-able into the brick. So basically all you would have to do to use a game for some quick fun is to load the build, which will then place the one brick cartridge into the BES. Basically instead of using the pixel screen for relays, the controller buttons call functions in the brick, which does some quick variable checks and recolors the screen to be correct.
Current Progress: Right now, all I have completed at the moment is the screen, scoreboard, which will be used for some games, and the actual console.
All of which are relatively simple events.
Basically it's gonna be awesome whenever I finish it.
Here are some pictures.

^This is basically the console I have made. It will improve visually, and event...lly... over time. The slot in the front of it is where the cartridge will be loaded into. Basically it just clears the screen, and relays this one brick. That one brick will sort of, "Activate" The cartridge so the controller can start working. The power button is in the back of it, and after I make my first game for it I will modify it so that it will work properly.

^This is the television/display. It really doesn't serve much of a purpose rather to be a constantly changing canvas for the cartridge to color, but then again it doesn't really need to be attractive.

^Just another view of the prototype display.
Also, this is very heavily modifiable. Maybe after I finish it and get all the bugs worked out, I'll write a little guide to how to make your own games, but that's not completely likely. If you can pull it off though, basically all you will have to do is create a cartridge that works with the controller. I have not decided yet whether you will make a custom controller to work with the cartridge or if I can find some way to make it a little more universal.
Oh well.
Tell me what you think.