Reddit reviews Billboard Greatest Christmas Hits: 1935-1954

This would be a good start for ideas:

• Low's "Christmas" Album
  
  
• "A Very Scary Solstice" and "An Even Scarier Solstice" by the H.P. Lovecraft Society
  
  
• The Chieftans' "The Bells of Dublin" Christmas album
  
  
• Billboard Greatest Christmas Hits from 1935-1954
  
  And this Rolling Stone "25 Best Christmas Albums" list is great.
  
  Albums are always solid to play in the background, though it's easy to pick your favorites from here to jive with your work environment for a quality mix (depending on how long your party will last).