All I want for Christmas is You by Mariah Carey is my favorite contemporary Christmas carol. Although now that I’ve done the math (23 years old!) and looked back at the history of this song, you could probably make the argument for categorizing it as a classic.
Either way, it’s an upbeat, cheerful song that feels like it was made to be sung at top volume in your car on the way to a party or during holiday preparations. You can’t go wrong with any version out there, but I really love this performance of Mariah with Jimmy Fallon and The Roots accompanying her with classroom instruments.