Halloween // Suggestions for Halloween Party Themes

This year will mark our 10th Annual Halloween Bash at our house (last year would have been 10, but you know...) and we need to pick out a theme soon! I would love your suggestions. We'd like to stay away from "plague" or "apocalyptic" type themes since we've all had about enough of that...with the one exception of zombies. Any themes you would love to dress up for or see at a party?

*edited to clarify this is a party for adults