For the past few years, I've inflicted this quiz on colleagues / family / friends, and it's proved quite popular.
So now I'm going to inflict it on you lot :) [Insert evil laugh here]

Attached is a spreadsheet, containing acronyms to title / recognisable line from 125 different Christmas tunes - carols, pop songs, novelty/parodies and traditional. All you have to do is work out which tune is which.