Amazon.comDeplorably cute and brazenly sentimental Christmas music comes in many shapes and sizes, but when it comes in the form of these hugely popular twins you know that if your kid is a fan, it's going to cost you. Mary-Kate and Ashley aren't confident songbirds, so their many friends do the singing. The arrangements are generally slick, uptempo dance-pop versions of seasonal standards ("Sleigh Ride") plus a "Christmas Carol Medley" that is rivaled only by another precious medley titled "Swingle Bells" and a couple of personal tunes ("I Do Believe It's Christmas Eve" and "What Christmas Means to Me"). With the girls' friends attacking the songs as if their day jobs depended on it and the twins warbling their parts with the sort of self-consciousness that works better in their videos, this is one party for which adults will be happy to be left off the guest list. --Martin Keller