It's a list of movies people like. The whole notion of "best of all time" is dumb, because there's no way to judge such a thing without going into full on movie elitist mode. This is a list made by average people who don't give a fuck about the "art" of movies, they just go by what they think is fucking awesome.
I can't believe there are so many people blown away by Dark Knight being on the list. "People really like the 4th highest grossing movie ever!?" <--