Mariah Carey's "All I Want For Christmas Is You," forever devoid of Christmas flaw.

'Tis the season to be jolly--and ICONIC. And to celebrate Christmas, we're bringing you two of the most legendary Christmas tunes ever, by two of our favorite music icons: Obviously we're referring to Mariah Carey's "All I Want For Christmas Is You" and Britney Spears' "My Only Wish (This Year)."

Now, we're not going to say that these are quite literally the only two Christmas songs that matter (after all, we did gift you with 30 holiday songs that don't suck), but if we were stranded on our own lonely little tropical island and could pick only two Christmas songs to listen to on repeat with our only friend, the volleyball, it'd be these two...hands DOWN.

Mariah Carey's "All I Want For Christmas is You," which was originally released back in 1994, isn't just a Christmas song; it's the ultimate Christmas song. (No, really, it's the best-selling Christmas single of all time.) Every fiber of its festive DNA sparkles and shimmers with the snuggly sensation of nestling in front of an open fireplace with a mug of hot cocoa, some warm blankets and dem babies.

As soon as the new "American Idol" judge kicks off the track with that life-altering line "I don't want a lot for Christmas, there is just one thing I need...," it's on, every single time. But like Britney's "My Only Wish," we ask ourselves: What could the world's biggest diva possibly need? A charm bracelet? Glitter on Blu-ray? A fiber-optic wall hanging of cherubs? (Oh wait, she's got that, too.) Nope, just like Britney, all she wants is a little lovin'.

It goes without saying that the vocals on "All I Want" are scientifically free of flaw, but by the time Mimi truly emancipates herself on that ginormous earworm of chorus -- THAT CHORUS! -- the angels themselves above are busy searching in vain to find their snatched halos. Mrs. Claus could truly never!

The song's been covered, remixed and reinterpreted in countless ways in past years -- Justin Bieber had some fun last year serving up a super festive remix of the track. But at the end of the day, all we want for Christmas will always and forever be Mimi.

+ Watch Mariah Carey's "All I Want For Christmas Is You" video.

"Merry Britmas to y'all, and to y'all a good night!"

There's only two types of Christmas songs in the world: The ones that slay (sleigh?), and the ones that observe. Britney's "My Only Wish (This Year)," originally released on 2000's Platinum Christmas and penned by writing team Brian Kierulf and Josh M. Schwartz (fun fact: They wrote a bunch of tracks off of Britney, AND they wrote Willa Ford's "I Wanna Be Bad") will forever be the most Spearitual song of the season. (So please, take several seats, "O Come All Ye Faithful.")

With those Christmas-y bells a-jinglin' in the background (B's no stranger to "Jingle Bells," after all!), Brit coos us her sugary-sweet wish list for Santa. But just what does the pop princess-turned-Queen of Pop want for Christmas, anyway? Not a toy soldier, we can tell you that much. Vanilla candles? Starbucks gift cards? Nope -- she's waiting for her one true love! "He's all I want, just for me/Underneath my Christmas tree," the living legend swoons.

There's ample prophesying into the future as well: "I signed a letter that I sealed with a kiss," she sings, predicting her 2011 Femme Fatale track, "Seal It With A Kiss." "I want my baby, baby," she sing-songs, an obvious allusion to 2008's Circus closer, "My Baby." That's our Prophetney, alive and well!

Like every other work in her blessed discography, Britney's "My Only Wish (This Year)" isn't just an iconic game-changer -- it's the most cool, funky and urban Christmas song of all time. Merry Britmas, everybody!

+ Watch Britney Spears' "My Only Wish (This Year)."

Photo credit: Getty Images; Michael Caulfield/WireImage