I'll skip over the story and the themes. Other commenters have said wonderful things about that.

Let's talk visuals.

I just have to say I was blown away by almost every single shot of the movie. The black and white color looks gorgeous, and the indoor shots have lots of shadows and texture. The outdoor shots seem overexposed, brilliant, artificial and almost unbearable. The criterion version just looks superlative.

Watch the dinner scene at the start where the man's brother in law is getting drunk with Tony. They are yelling, and having a time, and the camera dives/sweeps/rapidly turns around and falls. It conveys the dizzying nature of the conversation. The outdoor scenes in the first half of the movie have lots of bustle and activity, with lots of turns and shifts of perspective. People will remember the historical themes, but please don't overlook the amazing cinematography (which rightfully doesn't call attention to itself but enhances the emotional impact of every scene). In one scene (where Person X hits Person Y), camera conveys the claustrophobic, almost paranoiac perspective of Person X and sets the rest of the action up. We just knew what was going to happen next here.

The dream sequences/surreal effects were modest and didn't seem too fantastic; they were small enough for a small man overtaken with fear.