The most important aspect of this film, is its historical importance.

Rating: 10/10 (5 May 2005)

The most interesting aspect of this film (and something to keep in mind as you watch it) is the tone set early on, that this is a period in which, and a film made while the world still was not who would win the war!! It was filmed in 1941-2, while Nazi Germany still had a FIRM grasp over Europe, the Allies were behind in many aspects in the conflict, and it shows in the film! The insecurity of the people watching this film at the time about how things were going to turn out is the most fascinating part of watching Casablanca! Think about it: When this film was being made and even during its release, people were wondering daily if Europe was going to remain in the hold of the facists, and if the Americas (North and South American Continents) were going to be the last part of the world left as "free" nations! Whenever one of my friends asks me about this movie when they see it on my movie shelf, that is what I tell them---and it makes them all the more interested in seeing it. Just to be able to get a glimpse of the Insecurity the allied nations & citizens felt about the future, is perhaps the biggest reason for people to watch it.
So much is made about its perfect style, dialogue, acting, etc---which is true and certainly helps---but to me, the most important thing to keep in mind while watching Casablanca, is that at this time, people were really concerned that the Allies might not be able to 'totally' win the war. By totally I mean, being able to not just stop the Germans and Japanese, but be able to push them out of the tremendous areas of the world that they controlled when this film was made! Add to that, that at the time there was such an Isolationist movement in the US, that there were millions who felt the best that could be achieved was a stalemate which would keep the western hemisphere free, with the eastern hemisphere under the influence of Germany and Japan. Thats part of the reason why you hear the actors make comments about "Isolationism is no longer practical in todays world" etc.
Just watching Casablanca with that perspective, should make even the people who aren't thrilled with noir movies, at least view THIS film a little differently from a historical perspective---since it is literally a snapshot of the Allied uncertainty at the time. Just my two cents, but thats really the main reason I love watching this film, and why I repeat view it to watch for that feeling within it. If you haven't seen this film yet, you're missing a piece of history!