In no particular order except that I think the top 5 are among the worst of the worst.  More could be added I'm sure, but these are some of the most hair-ripping, ear-bleedingly bad ones.  I focused on original compositions and particular incarnations of well known songs that have become ubiquitous or just really stood out for their unique awfulness.  So, for example, there are any number of bad versions of every Christmas hymn, but Twisted Sister made the cut with "Oh Come, All Ye Faithful" for sheer audacity.
  1. Last Christmas, Wham! (re-incarnated by Glee and Taylor Swift)
  2. Wonderful Christmas Time, Paul McCartney
  3. Santa Baby, Madonna (and many others of course)
  4. Christmas Shoes, Newsong
  5. Same Old Lang Syne, Dan Fogelberg
  6. All I Want for Christmas Is You, Mariah Carey
  7. Santa Claus is Comin’ To Town, as destroyed by The Boss (no disrespect Bruce)
  8. Christmas in America, Kenny Rogers
  9. Don’t Save it All for Christmas, Clay Aiken (Celine Dion's version was a close runner-up)
  10. Grown-Up Christmas List, Amy Grant
  11. Christmastime, The Smashing Pumpkins
  12. Dominick the Donkey, Lou Monte
  13. 8 Days of Christmas, Destiny’s Child
  14. Merry Christmas, Happy Holidays, *NSYNC
  15. Mistletoe, Justin Bieber
  16. Oh Come All Ye Faithful, Twisted Sister (in the style of We’re Not Going to Take It)
  17. Please Daddy (Don’t Get Drunk this Christmas), John Denver (sorry JD, but what were you thinking?)
  18. Santa Claus Lane, Hilary Duff
  19. This One’s for the Children, New Kids on the Block
  20. You Make It Feel Like Christmas, Neil Diamond

There were at least three that didn’t make the list because they were just so wrong I didn’t even want to spread awareness of them.