In her book Advanced Screenwriting Linda Seger talks about “the ever-present identity theme.” She explains that some examples would be be finding one’s identity (Dead Poets Society), holding on to one’s identity despite oppression (Erin Brockovich), and finding one’s identity within a sport (Rocky).
“If we look at some of the Academy Award winners of the 80s and 90s, we can see an identity theme shimmering through many philosophical, theological, and/or psychological ideas.
Raising Your Script to the Academy Award Level
Certainly this years Oscar nominations, including The Wrestler and The Curious Case of Benjamin Button, has its share of films that deal with the theme of identity.
Related and much more in-depth look at the theme of identity: Writing Beyond the Numbers (tip #8)