I never celebrated Christmas growing up. I was raised Jewish, so we did Chanukah (8 nights in December).
After getting married and having two children, we celebrate the commercial and fun side of it, with the lights and presents, and just a few times with an artificial tree.
I notice that some of the rituals (pagan origin?) of Christmas seem to have more in common with Buddhism than Christianity. For example:
Christmas tree: Bodhi Tree
Lights, decorations: Enlightenment
Colored lights: The five colors emitting from the Buddha at enlightenment; red, yellow, blue, white, orange
Presents: Sanghamitta brought the gift of the Dhamma and a Bodhi Tree sapling to Sri Lanka. Her poya day is in December.
Perhaps all the more reason, we Buddhists should celebrate.