Jeez, Intestinal Chaos, sound like you have it worse than me. I can't do a list like that because it'd have about 4 dozen people whose only purpose is to sit there and get drunk.

Much as I gripe about them, there is one good thing about each of my parents.
My mother doesn't know how to punish anyone. This, on the downside, means I am in charge of all parenting aspects of her home but have no authority, but on the upside, means I can sit there and get trashed on Listerine and she won't do anything.

My father doesn't care whether I live or die so long as I'm there to babysit when he wants to go to the bar. Therefore, if I make a few well placed comments about the house burning down, I can usually get the freedom to go do anything I want.
So my Christmas tends to be spent sitting there in a dark corner, ignoring all life on the face of the earth, and occasionally answering a few questions or something. Then opening presents, cynically imitating the younger children when they open their presents. "Omigosh! Just what I always wanted!" I eat if I'm hungry, usually not much. I ignore all requests by older people to discuss anything that's going on in the teen world, my life, or anything at all, based on the fact that they tend to sit there doing much the same as lesser bullies: repeating what you say, changing the voice to make it sound retarded. So I ignore all people older than, say, 30, in my family, as they tend to be pretty freakin' stupid usually. I sit there and listen to rock with my headphones untill my bleeding ears short the headphones out. Then pretending I still have rock pounding in my ears when people try to speak to me.
The one thing that makes this even slightly bearable is the loot.

As for Christmas being a bastardized pagan holiday, I believe the deal with that is that they weren't quite sure exactly when Jesus was born, so they picked a time close to the winter solstice to celebrate. BTW, winter solstice is tomorrow.