Most of my holiday decor takes the form of Christmas tree ornaments. I have so many that are significant and cherished more than others -- see previous entry about all the stuff my son has made for our tree. And then my Mom gives me ornaments every year in my Christmas stocking, and the ones she gives me are particularly cherished. And then there are the ornaments I pick up when we travel, which is something I just vowed to begin doing a handful of years ago, so I don't have a ton yet. What we do have: a gold glass ball ornament with an Inukshuk painted inside of it that we got in Canada last time we went up; and a giant red glass Mickey Mouse head with Mickey clothes painted on it that we got at Disney World last year.
A few years back my Mom gave me some little glass ball ornaments with white snowy owls painted on them -- Hedwig from Harry Potter, essentially. I love them. Oh, and my favorite ornament is this little purple "love bus" I picked up at a Christmas store on the Pearl Street Mall in Boulder a few years ago. It has flowers and peace symbols and hippie stuff on it; it's Dept. 56. I love it and always have to find a very prominent spot on the tree for it.
We also have a little statue of Mickey Mouse dressed as Santa that my Mom bought for Daniel the year the three of us went to Disney World together, to remind him of what a great time she had with him there. That's a special piece too. It's by my favorite Christmas artist, Jim Shore. He does folk art painting on wood figurines, in bright colors. We also have a Nativity scene by him that I like to just leave out all year long because it's so lovely.
Honestly? I'd leave the tree up all year long if I thought I could get away with it. And wouldn't have to find a way to dust it.