Tele's right about "kids" (Ethan's age through mid twenties or so) not really caring much about films before they were born.
A lot of them, when you ask them their favorite movie, will say something modern. I've heard Lord of the Rings, lots of Disney/Pixar Films, Mean Girls, Harry Potter, A few hipster choices like (500) Days of Summer or Perks of Being a Wallflower, I've heard a few Pulp Fictions, Titanic, maybe a few Star Wars and Back to the Future, sometimes something recent that's come out like The Avengers or Hunger Games (these usually change within a year) etc.
Given, this is all anecdotal of what I've heard from that age group. And I can't say the older group is any different because my parents favorite films are The Big Lebowski and Jungle Book. A Disney film and a modern film, but I guess more inspired choices.
And mine constantly changes, but if you asked me right now Id probably say Raiders of the Lost Ark.
Given this is just from sampling the favorite movies of people I know, but I rarely hear references to obvious ones like Wizard of Oz or It's a Wonderful Life.