My top fav is probably Mariah Carey's "All I Want for Christmas is You".
I also like The Christmas Shoes, by New Song. Make's me cry everytime, but SO good. It really makes me appreciate what and who I have every year for the holidays.
Oldie but goodie is definitely Merry Christmas, Happy Holidays but *NSYNC
My Only Wish (This Year), Britney Spears
My last but definitely not least favorite is This Christmas by Joe
Ok...so they might not be as new as some, but they're still my favorite! :) They all put me in the Christmas mood.