This is what we found on Wikipedia regarding the Fairytale of the Pogues:

"Fairytale of New York" is a song written by Jem Finer and Shane MacGowan and recorded by their London-based band the Pogues, featuring English singer-songwriter Kirsty MacColl on vocals. The song is an Irish folk-style ballad and was written as a duet, with the Pogues' singer MacGowan taking the role of the male character and MacColl playing the female character. It was originally released as a single on 23 November 1987 and later featured on the Pogues' 1988 album If I Should Fall from Grace with God.

Originally begun in 1985, the song had a troubled two-year development history, undergoing rewrites and aborted attempts at recording, and losing its original female vocalist along the way, before finally being completed in August 1987. Although the single has never been the UK Christmas number one, being kept at number two on its original release in 1987 by the Pet Shop Boys' cover of "Always on My Mind", it has proved enduringly popular with both music critics and the public: to date, the song has reached the UK Top 20 on twenty separate occasions since its original release in 1987, including every year at Christmas since 2005. As of September 2017, it had sold 1.2 million copies in the UK, with an additional 249,626 streaming equivalent sales, for a total of 1.5 million combined sales. In December 2023, the song was certified sextuple platinum in the UK for 3.6 million combined sales.

In the UK, "Fairytale of New York" is the most-played Christmas song of the 21st century. It is frequently cited as the best Christmas song of all time in various television, radio, and magazine-related polls in the UK and Ireland, including the UK television special on ITV in December 2012 where it was voted The Nation's Favourite Christmas Song.