I don't know if you guys do this, but we get very territorial over whose ornaments are whose.

Us too. In fact, each one of us has our own set of boxes in which we store the ornaments during the rest of the year... cause we can't have them mingling with each other! noooo! We also each get to buy one new ornament every year, too... which means that the tree gets more and more crowded as time goes on. Last year there wasn't even enough room for some stuff.