What's the rarest or most unusual computer-related item do you own?

[JP Hindin]

I have an nCube2 with the front-end Sun 4/470, card, cable and software. I 
think having a complete system is probably reasonably uncommon.
I have no documentation on the thing at all, though, so I've never 
actually powered it up. If anyone has anything, I'd love to hear from you.

Certainly less so in rarity given the numbers manufactured, but I think to 
be retained in private hands, a Cray J98.

I'm not sure if it falls in any of the category above, but I have a fully 
stacked out E10k with about two machine's worth of spares. That's my 
favourite system just because I always thought they were the sexiest 
system ever... when I was first entering the industry back in the late 
90s.

  - JP