A single six-sided die of randomly chosen color and style, with an engraved word balloon containing the phrase "SON OF A BITCH!" inked in white in place of the "1" side pips. The ink for the other sides may be in a different color.
You could probably collect enough Metal Earth spacecraft to make a timeline of our progress. It's pretty neat to see how far we've come, and imagine how much farther we have to go.