So my score is 29... I had to add the famicom disk system, the turbo duo and a tele-sports radotin (Pong clone), but if I cheat and add some that are co-owned, I can add a GBA SP, a GBA, a Gameboy Color, a Wii, an Xbox, an Xbox 360 and a Nintendo 64 for a total of 36! Oddly I was 99% sure to own...