Not sure I would say best (thought the story sort of ties together in the end), but a movie that certainly hurt my mind a bit was
The Holy Mountain.
I think it is from 1973. It is impossible to explain other than to say that the insane crazy that it appears to be, does tie together. It has a background topic that is important and well ahead of its time (economic issues controlling us all).
http://en.wikipedia.org/wiki/The_Hol...281973_film%29
Was funded by John Lennon, did not know that until I looked it up now.
But the movie itself I think was just cast and crew on a total LSD trip for a few months. Within the first five minutes a drunken Jesus who has pissed himself is put on a cross and stoned by kids, where he proceeds to scare off the people who throws stones with RAAAAAAAAR sounds and he has a joint with a little midget missing his arms and legs (real). Then they travel to a town where they shoot a bunch of people on a parade with skinned and crucified dogs while tourists watch and take pictures of bodies, soldier has sex with a tourist next to them, then you pan to a model city filled with toads dressed as aztecs which are then blown up while jesus jumps around. Actual dialogue up to this point is 0.
I dunno. That is just few minutes. It is a visual trip so to speak, with points that tie together, but it is hard to do it in one sitting. Old man pulling his glass eye out giving it to the child prostitute coming out of the church made me look away.
As to regular movies
The Matrix (first showing at the movies, never seen those effects before)
Sixth Sense
Memento
Not watched a movie that surprised me in years. I hate movie trailers now. They give away far too much of the plot.