My favorite is a tattered old plastic Santa ornament, about 2 inches tall, him standing & with his sack of toys over his back. Most of the paint has peeled off, such that it is splotches of red & white. It is always displayed in the most prominent position on our tree.
Background of it...I don't know exactly how old it is, but know for sure it is at least 80 years old & possibly closer to 100 years old. At the first Christmas after my parents got married in 1950, they were dirt poor; to decorate their tree, my mom's parents gave them a box of old ornaments that they had (her parents were also dirt poor - her dad had a junkyard & she thinks the box of ornaments may have been something that he salvaged somewhere along the line). From what they've said, the Santa ornament pretty much looked the same in 1950 as it does now - in other words, like something that belongs in the trash.
When I was little, I fell in love with it. Since I was the baby of the family, I got my way & it became tradition that it was the first ornament on the tree, in the prime spot on the tree. That continued until I got married (I was the last child to marry, so was the last kid still in the house). On the first Christmas after I got married, we were all at my folks house for Christmas, and I noticed that Santa was not on the tree. I asked, mom said "I thought we gave it to you - it wasn't in the box of Christmas stuff." I was pretty unhappy, figuring that dad had tossed it. After we ate, we passed around presents & opened everything - shirts, typical stuff young adults get from their parents. I had one more box than my siblings, which I was told to open last. It was my old Santa ornament, which I promptly put on their tree until the end of the evening, then brought it home to put on my & my wife's first tree.
It will be tough deciding which of my two sons eventually gets it.