Well each of the Christmas specials I have only seen once, so my memory of most is a bit hazy. These are the specials:
1. The Christmas Invasion
2. The Runaway Bride
3. Voyage of the Damned
4. The Next Doctor
5. The End of Time
6. A Christmas Carol
7. The Doctor, The Widow, and the Wardrobe
8. The Snowmen
9. The Time of the Doctor
10. Last Christmas
11. The Husbands of River Song
12. The Return of Doctor Mysterio
13. Twice Upon a Time
Ranking
12. The Return of Doctor Mysterio
3. Voyage of the Damned
10. Last Christmas
13. Twice Upon a Time
11. The Husbands of River Song
The rest are too hazy to rank.
Any chance of a ranking of the Christmas Specials from the revised series? I remember the David Tennant intro as a favorite even though he's not really in it until the very end.
The first Christmas special (The Christmas Invasion) would be the one you remember.