"Don't say you don't know me, because I sure as heck remember you!"
We all know how fun and entertaining the movie is, but have you ever read the screenplay for Groundhog Day? Did you know that the reason Phil Connors is forced to repeat the same day over and over again is because he was cursed by a scorned girlfriend? Or that the length of time that it takes him to break the curse is ten thousand years? Then maybe you should read Danny Rubin's hilariously dark and twisted, yet sweet and uplifting screenplay.
One thing I will say, it's difficult to imagine anyone but Bill Murray in the role-- almost as if it were written for him. A sure sign of a well-crafted screenplay. I give Rubin kudos just for creating the character of Ned Ryerson.
(you can read the PDF version of Groundhog Day here)
(update: with his usual keen insight, Billy Mernit has a deeper look at Groundhog Day over at Living the Romantic Comedy)