I typically look out for party ideas which are unconventional and out of the box. I think that Youtube is truly a great resource of this type of tips. All you will have to do is browse through Youtube and perform a search for "birthday party suggestions" and you can find hours worth of clips with countless very good suggestions. The trouble is, who has the amount of time to see them all? So I am on a regular mission to gather some details to save me and perhaps others some time.
Here is an awesome video with some insane party ideas - https://www.youtube.com/watch?v=wUlJSgYGmFw
Hope you find some good ideas for your future party on Youtube!