This song has been sung my many different artists. John Lennon. Robbie Williams. Diane Ross. Christina Perri. Carly Simons. The Alarm. 

But my favourite version is the one by Celine Dion. 

http://www.youtube.com/watch?v=WCRDkzsWWtM

A Thousand Years - Christina Perri

Beautiful, slow, love...just perfect

http://www.youtube.com/watch?v=OHkvan-NFnM&feature=channel&list=UL

Jar Of Hearts - Christina Perri

So sad, yet so touching and in a way so true. Loved this song from the moment I first heard it. 

http://www.youtube.com/watch?v=8v_4O44sfjM&feature=g-vrec