One of my favorite Christmas memories was the time my dad and I went and bought Christmas for a family in our ward during the early 90's recession, and we went on Christmas Eve, left it all on their doorstep, parked the car way up the street, and then used my dad's "carphone" to call them and tell them to go outside. That was a good feeling. If I get the Bah Humbugs, I just try and do something for someone else.
I think the celebration of the Savior's birth isn't that big a deal, because we celebrate his life every day, every Sunday, etc. I always view birthday celebrations as for the living, and while I believe that Christ lives again, I think that observance of his birthday doesn't really matter in these postmodern times. I wouldn't hold a birthday party for someone who couldn't be there. I know this sounds obtuse, but if I want to celebrate Christ, all I have to do is go to Church, or read the Scriptures, or pray. Christmas is more about family and friends and feasting during the lean Winter months of the Northern Hemisphere. I am indifferent to the "Jesus is the reason for the season" slogans because they ignore the 3500 years of history of Winter Solstice observance that was co-opted to bring the pagans into the Church. Again, I'm sure this will irk some people, but while we do read Luke, and tell the stories, I think that secular holiday traditions, in moderation, are fun and wholesome, and designed to make us happy, and are more important than religious foci.
Really, Christmas to a child, is magical, and when we get older, we can't feel that magic because we know who Santa Claus is, and we know what things cost, and try as we might, we can't feel that elation and joy of running downstairs on Christmas morn anymore. Also, people we shared those memories with have died, and their absence bites the heart when we're around those we love because the loss of association is so tied to those memories that it staggers the soul. Nostalgia is at the root of the bah humbugs, and there's no cure for it other than making the sacrifice for the young ones, and trying to be Christlike via service instead of worrying about honoring him through saying that Christmas is all about him, because it never has been.
Also, the 12 days of Christmas start 12-25 and go through 1-6. That's why January 6th is called "Twelfth Night."