It honestly depends on which way you want to go with this. i mean, do yuo want to be slutty, no offense, or not so much? do yo uwant to be funny or daring? are you going as a couple or even a group?
with all that being said, I'd say go outside the trends. Everyone's gonna be Harry Potter or the sexy devil. How about go as a milkshake? you know, my milkshake makes all the boys. any way. just wrap at tube big enough to go around you in any color paper, brown white or pink works. then get a bunch of balloons the same color and glue them to the inside of the tube. get a mailing tube and wrap it in white paper then paint a red stripe around it like a straw. you wear it by attaching loops for the whole thing to hang on your shoulders like overalls.
of course you could always go as a zombie version of pretty much anyone. my daughter's going as a zombie girl scout. i'm dressing as zombie cyndi lauper. my husband will be zombie don johnson.
you could go as a clothes line with someone else. but that tends to be alittle difficult if you have to go to the bathroom. it involves using a line tied between you and someone else and actually pinning clothes to it.
hope this gives you some ideas.