jbird added a few more:
- Submarine Command (1952)
- The Man from Atlantis (1977)
- Deep Blue Sea (1999) - While not technically about submarines, it takes place at an abandoned submarine base
- The Hunley (1999) - A TV movie based on the first submarine that was launched during the American Civil War
A sub also features in the plot of 1992's Under Siege w/ Steven Seagal, and they pop up in several James Bond films.
And on TV: