For me, it was spending the night of my wedding anniversary accompanying my son to his 13th birthday present - seeing one of his favorite bands in concert. So we wound up at the Fillmore in Charlotte in the rain. I live-tweeted the event at #moshpitdad, and here's my story.
It really was fun, because we did it together. I'm sure he and I will have a good laugh about this for years to come. That is, assuming he can still hear me when I speak to him.