I've always disliked X-mas.
The term, not the holiday.
I never thought it was right to abbreviate Christ's name to a simple "X".
Tonight, as I was searching for a Chirstmas word game for my son's classroom party, I found the following (at this site):
The word Christmas is derived from Middle English Christemasse and from Old English Cristes mæsse. It is a contraction meaning "Christ's mass". The name of the holiday is often shortened to Xmas because Roman letter "X" resembles the Greek letter Χ (chi), an abbreviation for Christ (Χριστός).
I guess I am proven wrong.
But I still won't abbreviate. Call me stubborn!