Before I say anything, I have to say that I loved this movie (because what I may say afterwards may sound like I didn't). Jim Sturgess and Anne Hathaway were perfectly cast to play the two best friends, and I have to say that she did a great job with the British accent!
The storyline goes from Dexter (Sturgess) and Emma (Hathaway) spending a night together after graduation, and then moves to that same day (July 15th), every year, showing the progression of their friendship, as well as their own personal lives. It's literally hilarious at times (Dexter the pompous TV music show twat in the early 90's) and completely heartbreaking (Emma putting her writing career in hold to pay the rent by working in a Mexican restaurant), but all in all the story works, especially seeing as it was shot quite beautifully.
It all was a little TOO close to real life for me though, I really thought I was going to see a cheesy love story, when in the end I watched a story unfold that could more or less be my life, and Emma's character was a LITTLE too close to home. Needless to say I bawled my eyes out. And you will too.
Piece of advice: don't watch this with your best friend if he is a guy (or if you are a guy and she is a girl), and bring a box of tissues.