My oldest (11 YO) DS went as Dwight Schrute from "The Office". We put him in a suit and tie, glasses, parted his hair down the middle and gave him a name tag that read "Dwight Schrute, Assistant to the Regional Manager, Security Threat" with the Dundler Mifflin logo. We also printed out some Schrute Bucks for him to carry around.

Youngest DS (9 YO) went as a gangster. His costume started out as a vacuum cleaner salesman (I was going to print him up a flyer to show to people that read 'OUR VACUUM CLEANERS SUCK!') but he liked the gangster angle better.

Almost no one knew what they were but they did have fun explaining it to everyone. My poor 11YO DS had SO many people ask him if he was Harry Potter! Huh?!