If you're going to generate a list of, "best movies," it would be meaningful to define what makes a movie, "great." The other problem is that films are made for very different reasons and intents: to entertain, to edify, to indoctrinate, to persuade, to generate revenue, etc.
For example, Leni Reifenstahl's, "Triumph of the Will," was nothing but a pure nazi propaganda piece, and yet it was highly innovative at the time in technical terms, was, and continues to be studied in film schools and certainly achieved the filmmaker's objectives with overwhelming success. Does that make it a, "great film"? In some ways, I suppose it does, but not one I would care to sit back and watch with a tub of popcorn.
Some films have tremendously gorgeous cinematography, and crappy scripts. Some have great scripts and crappy acting. Without any objective criteria, any "greatest," list is simply the subjective opinion of it's maker. If it's voted on by poll, it's little more than a popularity contest.
Best Tool goes to Joe Biden. They used that guy for everything.