Not because you’re tired of hearing them, but because someone did a definitive version that can’t be improved upon.
For instance, “The Christmas Song” should never be performed by anyone other than the Chipmunks. Any other version is just wrong.
What else?
Actually, while that is and will always be the definitive version, I never liked it. It’s way too gimmicky. Last week I heard Kacey Musgraves sing it her way on an NPR album review and I thought it was really sweet and if I’d never heard the chipmunks I would have thought it was a very nice song. Of course, YMMV.
[ul]
[li]Nat King Cole sings The Christmas Song.[/li][li]The Eagles sing Please Come Home for Christmas.[/li][li]U2 is good and all, but Darlene Love sings Christmas (Baby Please Come Home).[/li][li]Gene Autry sings Rudolph. Period.[/li][/ul]
Jingle Bell Rock. Bobby Helms did the definitive version. I’ve heard Hall & Oates and the Brian Setzer Orchestra perform it, but they sound like the original. They didn’t do anything unique to it, just a slavish soundalike.
Call me old-fashioned, but I think Christmas with the Devil should only be done by Spinal Tap.
“Christmas Shoes” should never be recorded again. In fact, it should never have been recorded at all.
Ditto “Christmas in America.”
I think some posters are missing the point of this thread.
The only version of White Christmas that should be allowed to exist beside Bing Crosby’s is The Drifters. All other versions, hit the road.
I actually was going to say Christmas Wrapping could only be done by the Waitresses, but I did hear a decent version from the Glee cast.
You have to admit, there’s no way “Christmas Shoes” could be done better.
There’s also no way it could be done any worse. 
Judy Garland did the definitive version of Have Yourself a Merry Little Christmas. She was singing it as a character in Meet Me in St Louis. There’s a certain bittersweet poignancy that fits perfectly with the movie plot. (Parents want to move the entire family away from her hometown to NY).
I’ve heard other versions. But imho none did it as well. It’s unlikely they ever will because they aren’t performing in that movie.
When Elmo & Patsy recorded * grandma run over by a reindeer*, they did the definitive version.
You don’t hear many covers because it was done right the first time.
Eartha Kitt doing “Santa Baby.”
Another one: “All I Want for Christmas is My Two Front Teeth” has to be done by Spike Jones and His City Slickers.
I also has to be done with a lisp; otherwise the song is pointless. I can understand why more modern singers don’t want to do that – it can be construed as cruel and mocking a speech issue – but if you don’t want to do it, then don’t sing the song.
“Merry Christmas, Darling” by the Carpenters.
This, definitely.
Thurl Ravenscroft is the only one to do “You’re a mean One, Mr. Grinch”.
Fairytale of New York by the Pogues.
(C’mon, don’t tell me none of you weren’t thinking about it.)
I rather like the Pretenders’ version. Chrissie Hynde does have a nice voice.
This version of The Cherry Tree Carol pretty much closes the book on reasons to record it.
I’ve never understood why any song or movie ever needed to be redone.
Special mentions that comem to mind:
Nat King Coles “Chestnuts”
Sinatra’s “Have yourself a merry”
Harry Simeones “Drummer Boy”
One of the best by a currently pop artist made for the season that never got any airplay in later years was “Christmas in Dixie” by Alabama. A nice smooth, well produced arrangement . . .
