Sangam (1964, 3 hours, 58 minutes)
Considered one of Raj Kapoor's finest films, Sangam stars the filmmaker in a love triangle with Vyajayantimala and Rajendra Kumar. The romantic drama of close friends torn apart by secret love and consequences remains one of the most memorable blockbusters of the sixties.
The length: While the four-hour duration is undeniably exhausting, the film boasts a truly compelling story and performances strong enough to keep the viewer going. With the plot including being drafted into the army, the assumption of death and ultimately a wedding, the length almost seems justified -- helping us feel Vyajantimala's eventual resignation.