City on Fire

This movie is the predecessor of many American movie storylines in which an undercover cop, in his effort to assimilate to the world of crime, loses himself. "Donnie Brasco" and "Rush" are such movies with a similar theme.

Tarantino very obviously lifted the plot for his "Reservoir Dogs," even though Tarantino's movie is more notable for its snappy dialogues and unbearable torture sequences. "City on Fire" develops the characters more, and gives them a background.

But other than that, the major difference between the 2 movies is that, ultimately, there's a very different take on the notions of honor, loyalty, and brotherhood - I was surprised by both endings, in very different ways.

This movie is also a good companion piece to "The Killer" by John Woo. Chow Yun-Fat and Danny Lee star in both movies, but in reversed roles of cop and thief.