Erik beat me to my post about the "budget" barrister's bookcase.
I am planning on using that ALOT in the desk unit I'm going to build to go with my arcade cabinet.
The only change I would make to his design is that you need a stop at the bottom to keep the panel from getting kicked IN when it's closed.
Also, you want to make the pivot dowel, and dado slot significantly smaller than the width of the wood you are using, so that it will stop flush with the front, and not split the wood when in use.
I haven't actually built one of those yet, but I'm guessing 1/4" dowel/slot would be sufficient for a 3/4" thick panel.
I probably wouldn't build it out of MDO either.
I think you'd run some real risks of splitting the wood over time.