It's the h-h-happiest time of year!
I think for me it's mostly residuals of how it felt for me as a child. I remember lying under our tree, how the pine smelled, how the colored lights made the inside of the tree look like some sort of quiet paradise... the pretty Christmas tunes playing in the background.. surrounded by gifts I was all too excited to tear open...
As I've gotten older I've tried to make the season more about Jesus. I try to remember what we're really celebrating. Santa's nice and exchanging gifts is nice. But, to have a time of year based solely on that would be quite empty.
Today, Christmas is not as exciting for me as it was when I was, say, 8. For one thing, I'm not waiting for Santa to arrive. I live in the southwest now, so I don't get to see outdoor lights covered in ice and snow. And, when I do a tree, it is solely for myself. No one else gets to see or appreciate it. But, I still derive some pleasure from it.