You may recall I did one of these for a customer recently. I did one for myself yesterday!
Sony PlayStation, with mods:
* Stealth modchip (OneChip), disables copy/region restriction
* Replace GPU's NTSC master clock with 53.69mhz signal, for true NTSC timings (59.82hz vsync instead of 53.27hz)
* Replace the clockgen's 4.43Mhz subcarrier with signal from GPU, which changes according to PAL/NTSC mode; true NTSC instead of PAL60
* Blue power LED powered by laser sled; it flashes when a CD is read