An absolute plethora is the simplest answer and here are some of the annually posted suggestions...
Christmas Eve by David Lanz An Airus Christmus and Airus Seasons by Kurt Bestor The Xmas Albums by Wind Machine Star of Wonder by Peter Buffett A Romantic Christmas and A Family Christmas by John Tesh
The following are all available on the Windham Hill label:
Carols of Christmas by Various Artists A Winter's Solstice I-V by Various Artists Celtic Christmas I & II by Various Artists The Bach Variations by Various Artists The NutCracker by Modern Mandolin Quartet Hymns and Carols and Songs about Snow by Tuck Andress
While these are available on the Narada Label:
The Narada Christmas Collection Volume 1, 2 and 3 by Various Artists The Narada Nutcracker by Various Artists
Thanks to all who posted their suggestions especially Tom Mehren (email@example.com) and self confessed christmas music junkie, Judy Markworth (firstname.lastname@example.org).