The Last Song, Nicholas Sparks.
There's a reason why four of Nicholas Sparks' books have been made into movies - they are just THAT good. Granted, I have read almost all of his books, save for the one he wrote with his brother, so I am a bit biased, but I thought that this book was as good as all of his previous ones, and could definitely be made into a movie as well.
Ronnie (Veronica) is in North Carolina for the summer visiting her father, and as a New York City girl, she is not happy to be there. She then meets Will, however, who turns out to be her first love, and summer seems to be looking up; until she finds out a secret her father has been keeping from her. The ending itself was bittersweet, but Ronnie's ending is overall happy, if that makes any sense.
4.5 stars out of 5.