I think it's great that at least once a year much of the earth celebrates a day when we try to be good to one another. Whether it be Yule, Chunnuka, Festivus or commercial Christmas, it's still good for a person to do so, even selfishly.
I personally celebrate the birth of Christ, the love of family and friends, and the spirit of generosity and grace to all. Of course, my kids just simply love the gifts.
We get a smoked turkey from a local grocery store, and my whole in-law family (about 15 people) come to my house. We exchange gifts via Secret Santa (with wish lists published way before and a $100 dollar limit). We set up a tree and decorate it. We play mah jong, cards and console games late into the night. We make donations to various charities. We go outdoor skating and we drink hot chocolate in a thermos. I call my brother and his family in Vancouver and my parents in Hong Kong. While they were alive, I'd call my grandparents too. The next day we all go Boxing Day shopping. It's just one big long family fest. I try to kick out the relatives by Dec 28th or 29th.
Whatever your religious stripe (in my book, atheism IS a religion in every sense of the word except as an organization... it's a religion of self) such a celebration is a good thing. Of course if you hate your relatives or don't have any, I can see how some people might hate the festivities.
Unfortunately, Christmas is ALSO my wedding anniversary (coming up on... er... twelfth anniversary now). So it gets tricky how my partner and I want to spend it.
I celebrate... but because it's with my parents, it feels kind of forced, so I don't really enjoy it all that much. That, and my parents b-days are a few days before, and after Christmas, so harder to pick gifts :\
I especially hate decorating during Christmas time as well.