People are totally missing the OPs original theme. It is not films that are popular but shite. He was asking what films people mention they like, to appear "cool".
So that means long boring and heavy duty films that make you appear more intellectual and deep, or hard core and heavy duty by saying you like watching gangster movies etc.
For example, I noticed many people are now mentioning going to see Les Miserables at the cinema. I have asked them what they thought of the stage play. The blank look says it all really.
Many people like to look cool by saying the Godfather is a great film. The thing is it may be a good film, but great?
To me, it is way too long and the subject matter tedious. A truly great film appeals to a wide audience. So even if the subject matter holds no interest, the story and narration still shine through.
I love my films, and don't limit my viewing experience based on what others think. I also try to expand my viewing scope by watching random films. I have agreed to sit and watch the odd "chick flick" with the missus, only to find I actual enjoyed it. Same goes with kids films.
Film snobs like to look down at Disney animation type films, but some are really good. Same goes with blockbuster action films. I thought the original Matrix film to be stunningly original. Same cannot be said of the following films. The first Alien film was the same. I really like "Leon" is that cool?
Any way, to get back to the OP. All the Kill Bill films...cool maybe, poo yes!