I have a SNES and an OG Xbox if that counts. Not quite rare, but old indeed.
"Everyone is flawed one way or another, even the best of us, so why bother being Insecure "
Not sure any of my collection is "rare" per se but the least common out of all of them might be my Gameboy Colour. Though since I don't know how much that sold, it could very well be my Wii U.