One Direction Songs: Which Is No.1 On The Top 20 Biggest Selling List?

15. I Would

Several of One Direction's songs have been written by other artists, but 'I Would' was a collaborative writing effort between three members of fellow boyband McFly: Tom Fletcher, Danny Jones and Dougie Poynter. It's one of the more downbeat tracks of their collection as they sing not about partying or meeting mysterious girls, but about trying to compete with the scary tattooed boyfriend of their latest infatuation.

14. She's Not Afraid

'She's Not Afraid' threw in a little guitar riff here and there, giving it a distinctly edgier sound to their previous hits. This was a bonus track to various editions of their second album 'Take Me Home' including the limited yearbook edition, the Japanese limited yearbook and the iTunes Store deluxe. It may not be the most stand-out track of their back catalogue and it didn't venture into the Billboard Hot 100 - but Billboard magazine did place it at number 3 for the Bubbling Under Hot 100; a chart depicting the main singles that are yet to enter into the Hot 100.

13. Na Na Na

The other track to be produced by Matt Squire and another one that solely features on the German Edition of the 'Up All Night' album and the Souvenir Editions for Australia, Mexico etc. It is the B-side to their debut single 'What Makes You Beautiful' and one that they performed alongside it at the BBC Radio 1 Teen Awards. It's a light-hearted number about a love-hate relationship and managed a number 27 spot on the Irish Singles Chart - again, an impressive feat for an unpromoted tune.

12. Another World

'Another World' was one of the charting tracks from 'Up All Night' but didn't actually feature on the original album tracklisting. Instead, it appeared on the Souvenir Edition which was available in Australia, Mexico, the Philippines and New Zealand, as well as the German Edition. It was produced by the Grammy nominated RedOne and had a rather heavier drumbeat behind it than most of their tracks - amazingly, for a track that wasn't even on the main edition, it reached the UK and Australian charts at 85 and 66 respectively.

11. Up All Night

This is, as many 1D fans will know, the title track to their multi-platinum certified debut album and certainly rounds up the general upbeat party feeling of the album. There's even a nod to their fellow chart success Katy Perry in there - a small detail, but a massive emphasis on the harmony and non-competitiveness of pop music these days. It is one of two tracks on the record to be produced by Matt Squire, who's previously worked with the likes of Kesha, Demi Lovato Panic! at the Disco, HIM and The Used, and was compared to a Backstreet Boys track and LMFAO by Billboard on its release.