I routinely try to find party ideas which are unique and out of the box. I think that Youtube is truly a very good resource for these kinds of tips. All you will have to do is browse through Youtube and do a search for "event suggestions" and you are going to see hours worth of videos with numerous outstanding advices. The problem is, who has the amount of time to see them all? So I am on a regular mission to gather some notes so as to save me and also perhaps others some time.
Here is a great video with some crazy party ideas - https://www.youtube.com/watch?v=wUlJSgYGmFw
Hope you find a few good tips for your next gathering on Youtube!