I don't know about my rarest game, like a lot of people here I just have some random 7s and 8s (on Coleco, Dreamcast and Neo Pocket mostly) with nothing really standing out.

Rarest system, though:



That's gotta be like R7 + R1 + R8 + R6 or something, for what? R21! ZOL!! OMG!!

Plus R7 more:



RAWR!! It's teh r@r3st sistem evar! R28!!


...word is bondage...