There are a few ways to decide the biggest hits ever in Hindi cinema. If we go to go by cost to earnings it is very clear cut and Jai Santoshi Maa (1975) is by far the biggest blockbuster ever. Jai Santoshi Maa (1975) was made on a 4-5 lakhs budget and collected a distributor share of 5 crore which is 100 times its costs. Next on the list would be Maine Pyaar Kiya (1989) which returned around 15 times its cost but even that is still way below the returns of Jai Santoshi Maa. But the real mega blockbusters we believe are decided by the volume of public watching them in a particular era. Jai Santoshi Maa would not have been an All Time Blockbuster if it was a big budget film of that time while Maine Pyaar Kiya would have just about made it. There are seven films in the history of Hindi cinema till date (2010) which stand above the others. What these films did is smash barriers by a distance. If a huge blockbuster of their times were expected to hit a certain level, then what these films did was go much much higher than that level. They all practically went twice as high. The seven films are easy to pick out but the order after Sholay is debatable but the following list is how we see it to be.
1. SHOLAY (1975) - Simply the most watched and loved film of Hindi cinema by a distance. Dominated theatres for 25 years with umpteen re-runs. Business in re-runs was on many occasions higher than newly released films of the time.
2. Mughal E Azam (1960) - Smashed all records when first released and the amazing re- run with its colour version (2004) gives it number two position.
3. Hum Aapke Hain Kaun (1994)/Gadar Ek Prem Katha (2001) - Tough to split the two, Hum Aapke Hain Kaun basically changed film business while Gadar is the most watched film of the modern era (post Hum Aapke Hain Kaun) . Basically these films are the biggest blockbusters of the modern era.
5. Mother India (1957) - The first film to smash records by a margin. Business is similar to Mughal E Azam but impact of that film in 2004 re-run gives it edge.
6. Dilwale Dulhania Le Jayenge (1995)/Three Idiots (2009) - Tough to split the two, Dilwale Dulhania Le Jayenge was a huge follow up a year after Hum Aapke Hain Kaun and a 15 year (still going) run at one cinema in Mumbai. Three Idiots was the first true mega blockbuster since business became dominated by multiplexes. Another similarity between the two is that though they were the second biggest hits of their respective decades they were liked more by the classes than Hum Aapke Hain Kaun and Gadar so therefore have a better media perception than those legendary box office blockbusters.
Other huge grossers would be Sangam, Upkar, Bobby, Roti Kapada Aur Makaan, Kranti, Coolie, Ram Teri Ganga Maili, Maine Pyaar Kiya, Raja Hindustani, Kuch Kuch Hota Hai, Kabhi Khushi Kabhie Gham, Dhoom 2 and Ghajini but these films are well below the big seven. Some All Time Blockbusters are missing as they were All Time Blockbusters due to being smaller films and not huge takings at the box office.