Probably should have thought of this idea ages ago.
But I'm thinking of songs generally ignored by the world that would make interesting/divsersive/excellent BIG POP SONGS if the producers of X Factor got hold of them and gave them the gloss treatment.
Nick Cave and The Bad Seeds - Into My Arms http://www.youtube.com/watch?v=LnHoqHscTKE&ob=av3n (anyone could do this, and they could probably change the lyrics)
The Black Heart Procession - The Spell http://www.youtube.com/watch?v=g661Skdm2Wc&feature=related (would make a good bombastic Bond Theme style song)
Uncle Tupelo - Still Be Around (http://www.youtube.com/watch?v=di7ojryNFVs) - They'd tone down the alt. country (although this song doesn't really have it TBF) but it would still work.
I don't mean 'wouldn't it be hee-larious if Matt Cardle covered 'Packs of Three' by Arab Strap' - I think what I'm interested in is great pop songs that aren't really popular songs at the moment.