NINJAS (everyone is a ninja, or a power ranger, anything ninjy)
all pink party (both guys and girls)
ROBOTS AND NINJAS (even better)
shorts and ties (just like angus young)
homeless and hookers (this is not guy/girl specific either)
ghetto fabulous (get your thug on)
all stripes party (ANYTHING striped)
90's (grunge/ravers/ugly jeans/spice girls)
wear a trashbag party (CHEAP!)
bathing suit party (beachwear counts)
"upside down party" (be creative!)
be a different race for a day party (any race, bonus points for accents)