For all of the complaints about stagnation and a lack of imagination in Hollywood, the medium of film is hugely exciting precisely because it is still pretty much in its infancy. As viewers, we get the pleasure to live in a time where it seems like every few years there is a new groundbreaking technique being developed.
Whether it's James Cameron's use of 3D in Avatar, David Lynch's reckless narrative abandon in Mulholland Drive or the conclusion to years of careful setup in The Avengers, there is always something new to marvel at on the big screen.
The truly great thing about film is this has always been the case; the language of cinema is still being written and will continue to be honed and perfected over the following decades.
What's most interesting about the rapid development of film as its own unique medium is the way genre is treated. Movies have a way of borrowing dramatic ideas from other mediums (books, television, plays) and presenting them in a new light. The last 100 cinematic years have proven this and here's how...
10. 2001: A Space Odyssey
Sci-fi is a particularly open genre because it is mainly concerned with ideas. If you're making a sci-fi it can pretty much be about anything as long as you have a strong central idea to tie everything together. What makes 2001 revolutionary amongst big high-minded sci-fi stories that preceded it (The Day the Earth Stood Still, Invasion of the Body Snatchers, The Twilight Zone) is Kubrick's incredible attention to the details that make his ideas so impactful today.
Through a somewhat ridiculous attention to the details of the world he was creating, Kubrick was able to create a fully realized environment that had never been seen in a movie before.
This led to his futuristic vision being almost unnervingly believable, which gave him the creative license to do whatever he wanted. 2001 takes complete advantage of this by taking sci-fi into deeply philosophical territory that left many filmgoers scratching their heads as they left the theatre.
This is because 2001 took sci-fi away from being a silly/often looked over genre and proved it deserves to be held in more esteem than your typical B movie. Kubrick's film was so revolutionary that filmmakers today are still using it as a guide to understanding what makes a movie great.