Okay, so when I mentioned in my introduction post that some songs weren't specifically "about" Christmas, "Back For Good" is what I meant. As far as I know, it's not about Christmas. Not at all, actually.
Or, well—is it? Because would it really be such a staple of Christmas parties, even in television & films, if it didn't subconsciously reflect some sort of Christmas spirit?
Anyway, I've written about "Back For Good" before, but I'm taking this opportunity to elevate it in my personal pantheon from "somewhat guilty pleasure" to "perfect end to a holiday mix." Gary, Robbie et al: consider yourselves elevated.
But so, "Back For Good." Here's the thing: it's perfect pop, & the perfect song to end a holiday mix, or a movie, or a television special. But more specifically, it's the perfect soundtrack to a last dance, wherein you summon the courage to dance with whoever you've been watching all night. 
It's a new year soon, after all.
 Yes, I am sadly under the influence of the (always surprisingly sentimental) The Office Special.