Thanksgiving was my favorite for a long time, but in the past several years, the participation and reaction of my children has made Christmas my favorite. It's only inched out Thanksgiving by a slim margin though.
I love food. I love the menu we have on Thanksgiving. I love getting together and playing Risk, Monopoly or Spades with my cousins and extended family after dinner, and I love the Black Friday shopping the next day!
For Christmas, I love the meaning...I love hearing my children recite the entire Christmas story from the book of Luke in their school Christmas program. They did it in K and they'll be doing it again in 1st. I love the look on their faces when they come downstairs and see the tree for the first time on Christmas morning.