"You're either part of the solution or you're part of the problem." - Eldridge Cleaver
As you may have guessed, I have an aversion to school day parties. My first class nearly revolted and left me tied up in the supply room when I said No, my dear 5th graders, you may not bring cupcakes for _____'s birthday. For the 7th time. So quit asking!
Then I was a-thinkin'... How about one of those Guess Who I Am? parties where the students can each be assigned a person, place, maybe even a concept that was studied during the past year? They could know who they are ahead of time and research/prepare clues and answers to questions other students ask to figure out who or what they are, or they could not know and have to ask the questions of others. Maybe one visual clue, although costumes may give away some characters too easily. Students could be fiction, Charlotte or Poseidon or Katniss, they could be historical or current events figures, maybe even lava or pi depending on the student. Easily differentiated to many levels.
Throw in some apple slices and crackers and *voila!* we have a par-tay!