For me, it's just not Christmas until I've listened to at least some of Handel's Messiah.
Everyone knows the Hallelujah Chorus, of course, but I have other favorites:
Glory to God:
For Unto Us a Child is Born:
Ev'ry Valley Shall Be Exalted:
And, yeah, okay, it just wouldn't be Christmas without the Hallelujah Chorus:
One of my favorite live performances was at Samford University, my alma mater, several years ago. The University Chorale, the A Cappella Choir and a group of alumni who'd been in the various university choirs joined together to present Messiah. It was enthralling.
Enjoy the music!