I have been obsessed with collecting odd stuff for most of my life, but the most unusual object I have aquired so far, has to be an extraordinarily rare version of the Iron Cross. (WW1 issue, thankfully - no swastika!)
I'm sure most of you have at least heard of the Iron Cross, the famous German military award which signifies that the bearer has shown exceptional bravery in combat (or bought an Iron Cross on eBay.) It is made of blackened iron, with a silver frame. That's the standard edition - mine is made of brass!
That's right, a brass Iron Cross!
Apparently, these were sometimes issued to naval personnel because the regular model would quickly get rusty from the salty sea air.