Christmas number one - it's one hell of an achievement. Or at least, it used to be.

If you can believe it, 2004 was the last year that Ireland, the nation whose favourite Christmas song is 'Fairytale of New York,' has seen a Christmas song at the number one spot. Lads, what is going on? Allow us to investigate.

2004 may not seem that long ago, but that's 14 years of no festive song at the top spot. Our last "Christmas" number one was Band Aid 20's 'Do They Know It's Christmas?'- and even that was just a re-hash of the original.

You see, a year later, two words happened in Ireland that changed our Christmas number ones for years to come... Simon Cowell.

That's right, the 'X-Factor' arrived in Ireland. Having achieved huge success in the UK (but where is season one's Steve Brookstein now?), the 'X-Factor' arrived to Irish shores in 2005. Shane Ward won that second season with 'That's My Goal,' however he was beaten to the Christmas number one spot by Mario Rosenstock with his 'Gift Grub' single.

Leona Lewis secured the first Irish Christmas number one for the show with 'A Moment Like This' in 2006. At the time the 'X-Factor' was great, it was cool. The show created such a buzz around the country, that we were all feckin' hooked - it was the show to watch.

However, what occurred after this can only be described as a travesty in the music taste of the Irish people (no offence, everyone). From 2006 until 2013, the 'X-Factor' held onto the Christmas number one each and every year.

Throughout those eight years we had 'X-Factor' winners Leon Jackson (who?), Joe McElderry (sorry?), and even Sam Bailey (was she yer wan who worked in Tesco?). Nope, we don't remember them either.

If you can believe it, Ireland has also had more 'X-Factor' Christmas number ones than the UK. Just let that sink in for a moment.

However, the following years saw the 'X-Factor' dethroned from their Irish pedestal at last. We started to come to our senses, and start buying non-talent-show-related singles. Even though none of the Christmas number ones following these have been mildly Christmas related, it's been a nice 'X-Factor' cleanse.

Now, Christmas 2018 is fast approaching (15 days!), and there's a number of contenders who want to follow in last year's Ed Sheeran and Beyonce collaboration; while the music video was Christmassy, the song has nothing to do with the season. We see what you did there Ed, you sneakily brilliant songwriter.

It's pretty safe to say that current 'X-Factor' winner Dalton Harris won't be securing the top spot; most Irish people switched off this year. All signs are pointing to Ariana Grande's 'Thank U, Next' which might just win it. While the song isn't a Christmas song in any shape or form, the singer pays homage to classic 90's movies in the music video - and includes the 'Jingle Bell Rock' scene from 'Mean Girls'.

We won't know for sure what the Irish Christmas number one will be until it's revealed on Friday, 21st December. Who do you think will be number one this year? And what do you make of our Christmas number ones of the past? Let us know in the comments.

If you want to have your say on your favourite Christmas number one, take part in our poll here.