SNSD - Santa Baby
SNSD Jessica & Seohyun, Secret Jieun, & BEG Gain - Have Yourself A little Merry Christmas
SNSD Taeyeon - O Holy Night
Super Junior - Santa Claus Is Coming To Town
KPOP Idol - Jingle Bell
SNSD - All I Want For Christmas
& There is still many more. I won't put them all up but this are the one I remember and love the most. If there is time later, I would post up more.