Costumes I think you could make fairly easy and that are totally 80's.
Daisy Duke
Hulk Hogan (if you want to go as a man)
Cabbage Patch Kid (you could make some yarn hair)
Care Bear (add a patch to your shirt)
Rainbow Bright (striped socks, and you'd have to look up the rest)
Crocodile Dundee
Breakdancer (complete with boombox on your shoulder)
Michael Jackson (one glove, jeans, white socks, and a zippered jacket if you could find it)
Depending on your hair, you could try to make it do the Flock of Seagulls thing.
Punky Brewster
Still thinking....