As you can see, this is going to be different for just about everybody- for myself, I don't know if I can really name a "Best movie ever". It's too much a mood thing. If I had to pick a movie that was the biggest thing I've ever seen to hit the screen and become just... everywhere, everything, to everybody, it was the first Star Wars in 1977. Say what you will about Lucas, SW, or any of the rest of it- that was just... insane. Lines around the block for months on end, it was in release for over a year, re-released numerous times. People could not get enough of that, and it started to show up everywhere else, too, in references, parodies, and rip-offs, from TV to music- everywhere. I haven't seen anything like that since. No matter what "Yeah but..." you may throw- it wasn't like that. ET, Avatar, Titanic all made money, but do you remember a "Titanic Holiday Special"? I don't.