This movie is great for many reasons. Many of the things that make this movie great don't stand out very well by today's standards. But, if you look at the time it was made, this movie truly shines. First, one of the main characters is black. He is one of the heroes of the movie. And this is in a movie with one of the greatest actors of the era, Humphrey Bogart. Also, other than Sam, the intentions of the other characters are all rather ambiguous. One moment you'll see Bogie handing his friend over to the Nazis, next he's smuggling Polish rebels to American. The good guys aren't so good, the bad guys aren't so bad, and some you just can't tell. There were no shining heroes or slimy villians, just the gray that occupies the large space between them. In an era where all the heroes had to be pure, this movie went against the grain.