"All I Want For Christmas Is You" by SparklingTwilight
At nineteen Edward Cullen made a decision that would haunt him for the next ten years: when his best friend Bella confesses her unconditional love for him, he dismisses his own feelings, rejects her and offers to remain friends instead. Heartbroken, Bella leaves her life and home town behind and moves to New York to start fresh. But neither the change of location nor her focus on the job help her forget Edward and love for him. And so, one day, when Bella happens to bump into Edward's little sister Alice, she doesn't hesitate to accept an invation to the Cullens' christmas party.
Let me get this straight: this fanfiction is fluffy, fluffy, fluffy. Don't expect major drama or chapter after chapter of the two getting back together - this is romantic, cute, and yes, not necessarily realistic. But the wonderful christmas setting and an awfully sweet Edward really make up for that!
All Want For Christmas Is You is a one-shot. The story is rated T and thus suitable for teens over 13 years of age.