I enjoy many of the most reviled songs here. As a Paul/Beatles fan, "Wonderful Christmastime" is a longtime favorite; "Grandma Got Run Over By a Reindeer" is parody, people; and the Singing Dogs are just fun, nostalgic cheese. We only roll this stuff out one month a year.
As for songs I don't like...well, I've heard plenty of horrible Christmas songs that I couldn't stand and didn't have the time of day for. For example, I was once the recipient of a couple of volumes of an Internet acquaintance's Christmas rock song anthologies that were, IIRC, the ninth and tenth in a series. I imagine that he started out with two or three volumes of really good material. But by Vols. 9 & 10, he was really scraping the bottom of the barrell--crappy punk renditions and such that did nothing to evoke the holiday spirit for me. I gave them one listen over a decade ago and I can't imagine ever putting them on again. I also once bought one of those five-disc sets at Costco where each CD only has 30 or so minutes on it, so you're not really getting as much of a bargain as you think. It had a couple of things that I wanted on it, but much of it was filler that I couldn't stand.
So I'll have to single out songs that I've actually heard a lot in prior years....
"The Christmas Shoes"--My god, what saccharine crap. Glad I'm not alone on this one.
"Last Christmas" by Wham!--*blech*. This once held over six minutes of good space on my personal three-CD anthology (now an iTunes playlist) because it was a favorite of my adult ex-stepdaughter. Last Christmas, with the divorce in progress, I happily removed it from the playlist.
"I Believe in Father Christmas" by Greg Lake is so self-indulgently cynical that it ruins the holiday spirit for me.
"Do They Know Its Christmas?" by Band Aid tries my patience, but I have a very, very small sliver of fondness for it.
If I'm listening to an a station that's playing all holiday music, nothing will make me change the dial more quickly than Celine Dion...except maybe "The Christmas Shoes".