Don't know if anyone will read this, but someone needs to mention Space:Above and Beyond- River of Stars.

It opens with a brief history about an amazing Xmas ceasefire that happened during WW I. Then it jumps to a squad of space marines having their spaceship damaged and knocked out of a firefight with a force of mysterious aliens. Crippled, they drift towards enemy territory on Xmas day. While trying to get rescued, they grapple with what Xmas means to each of them, only to discover that one of the mysterious aliens they have been fighting this war against may actually be trying to help them.

It is thee best Xmas episode period. At least in my opinion. Can't have a list like that without at least mentioning this episode. 

Due South had a Christmas episode which I watch every year.  The Gift of the Wheelman.  LOL

 Space Above and Beyond!!!!!! I just got the soundtrack (3 discs) from LA LA LAND Records for $10. Sorry I forget about that one!

I liked that show.

 Great article and fantastic comments.  This is why I come to this website (I can read reviews of Les Mis elsewhere).  I am amazed that you can remember all of  this stuff.  I haven't seen half of these shows and the ones I did see I had forgotten about until you people jogged my memory.  Heck i forgot all about the 90's Fox series -  Space:  Above and Beyond, until you guys brought it up.  Thanks for the tips...I'll explore them.