1. R2-D2 ('Star Wars')
Basic Function: To speak in a series of beeps that only C-3PO can understand, but somehow wind up at the center of the action for all six Star Wars movies.
Good or Bad: He's certainly a force for good in the universe, but he definitely delights in poking fun at his hapless partner C-3PO.
Boldest Action: Storing the Death Star schematics along with Princess Leia's cry for help, a key move that kickstarted the events of the original trilogy.