We had a food fight one year when I was about 12. It started off as a disagreement between my parents over something trivial that escalated and ended with everybody arguing. I don't know who threw the first spoonful of mashed potatoes but it was a full on war soon enough.
That was so much fun I didn't even mind having to help clean up the mess.
One year when I was in college, my boyfriend (now husband) flew home from California to surprise me for Thanksgiving. He was in the Army studying at the Presidio, so I didn't even think he'd be able to get away. It was great.