I would say nothing. I celebrate Christmas, but other than it's Jesus' birthday, I don't see the big deal over it as you can always give someone a gift any time of the year. Don't need to be "forced" to do so on one day (or multiples if you count mother's day, father's day, and doomsda... er V-Day)
Each of the three first answers equally - and also ( I Am a Woman! ) the Shopping!, excitement, the food and sweets - And at the top of my list ; Christmas morning awaking with my husband, sharing a bottle of Champagne and strawberries with cream for breakfast in bed ! Heaven !
2 and 3 because my religion is not in that vein of Christianity 2 because I like getting stuff even though there isn't much I need or want 3 even though it's just me and my parents although I am spending it over with extended family this year