The only pinball rarity I own wouldn't work for this challenge, as it is not an actual pinball machine, but it would fit right in with the gaming theme of the whole show.
It's the only boxed example of the Entex Black Knight handheld electronic pinball game known to exist!
Entex-BlackKnightPinballBox.jpg
Oh, yeah, I forgot, I also have another rare pinball toy, Parker Brothers' Drac. Two, actually, both boxed, one still sealed!