I might do my "end table and lamp" costume again. I kinda liked it last time since whenever I was just sitting around at the party somebody would inevitably come over and place their drink on me, or leave a joint in my ashtray, or other such fun nonsense. I also think people were more open about just sitting down by me and talking since it was almost like talking to yourself but the lamp sometimes answered back.
I cut a hole in a board just big enough to sit on my hips and covered it with a tablecloth, wrapped my body in red cloth to simulate a lamp base, wore a lampshade as a hat...with various miscellaneous stuff on my table part.