Bunch of people have suggested it here and on BH. The easiest would probably be a PSP Go. Just make a fancy box for it, buy the TV out cables, and sync up a DualShock 3. Of course it should also have CFW because there's a plugin that gets around the whole "letterboxed 16:9 when on a widescreen HDTV" thing. That and the PSP Go is just awful without CFW anyway.