I recently rewatched one of my favourite films, The Graduate. In case you don't already know the plot, it surrounds the life of recent graduate Benjamin, who is confused and bored with life until he gets involved with a friend of the family, Mrs Robinson. That is, until a meeting with her daughter starts to confuse matters slightly.
Dustin Hoffman is brilliant as Benjamin (the role was apparently intended for Robert Redford which would've made for a very different film) and provides some real comedy moments. It also concludes with one of my favourite ever endings to a film, topped off with a beautiful soundtrack by Simon & Garfunkel which perfectly sums up the time period.