Heat (1995) was very, very good (like other things from 1995, hi). The plot, for a start: workaholic cop Vincent Hanna takes on an armed robbery case, committed by the crew of professional thief Neil McCauley. They are archenemies but also recognize something of themselves in the other, maybe a sense of determination, commitment. There's an amazing scene where Hanna stops McCauley on the freeway, he knows McCauley's guilty but can't arrest him for lack of evidence, so instead they go for coffee at a diner and talk, admitting that they'll eventually try to kill each other. There's a form of respect, of mutual admiration, between the two men. And the whole thing is based on a true story.
Besides the plot: the directing, the photography (colors! Lots of blue tones, a significant portion of the film takes place at night), the acting (Al Pacino and De Niro), all *chef's kiss*.
Not surprised that the film has been so influential, in the movie industry (it inspired directors from Christopher Nolan to Mia Hansen-Løve)... and in armed robberies.