In case you want an x86 board instead of an ARM Rasberry Pi Here is a decent option: https://www.kickstarter.com/projects/263025908/jaguarboard-x86-based-single-board-computer/ The campaign has already been funded and hardware has been shipped Hopefully the success will result in building more boards. I have always loved the idea of a Rasberry Pi, but my investment of x86 games won't run on an ARM processor. So this would be an option for a light gaming project like DOS games, old games or even a media center.
