I saw this movie when I was ten, and for some reason remembered very little of it. I watched it recently and loved it. As demonstrated by Alex Sokoloff, it is a great example of plot structure: great stakes, awesome characters, cool opening scene, etc. And it's a Steven Spielberg film, which says enough by itself.
Set during World War II, the plot involves Indiana Jones, a hunter of ancient archaeological treasures, who must find the Lost Ark of the Covenant, which holds the Ten Commandments of biblical legend. Indy does not believe in myth, but the Nazis are after it too: they want to give their army unnatural powers. Indy travels to South America, Tibet, and Egypt throughout the film, and the settings by themselves are amazing. He solves age-old puzzles and fights plenty of villains, and the romance is also well done. I love the capuchin monkey (Ruby, was it?), who also acts in Night at the Museum and Pirates of the Caribbean, among other things. Monkeys live long. The villains are really creepy, and the adventure is a lot of fun. I have yet to see Indiana Jones and the Temple of Doom, which I heard is good but not as good as this, but this is a great adventure film. I give it an A.