1. "The First Noel" Let's start with the very worst. The whole point of this lethargic song is stating that baby Jesus is "the King of Israel," clearly exposing "The First Noel" as a war cry for a Judeo-Christian dictatorship in the Middle East, a war cry that foments bloodshed to this day. Every time you sing this song, a Palestinian dies. As if murder-by-lyrics isn't awful enough (take note, Phil Collins, re: everything you ever did), the chorus is basically just a long torture of vowels—noooooooeaaaaeeeeeeiiiiiiooooel—butchered over and over again by every Caucasian choir that has ever attempted it. Just awful.
2. "Baby, It's Cold Outside" This is an unacceptable Christmas song because it isn't a Christmas song at all, yet it's played all the time in conjunction with Christmas music. It's more like a cross between The Silence of the Lambs and an unpaid advertisement for Rohypnol.
3. "Santa Baby" (as Sung by Madonna) Unlike Eartha Kitt, who recorded this song first, Madonna doesn't actually have a personality. Sure, Madonna puts on airs of being a material girl, obsessed with riches and flash, but then again, remember when she put on airs of speaking with a British accent? Yeesh, lady. It doesn't help that Madonna can't sing. She sounds like she's auditioning for the Chipmunks.