The most successful actors list can vary from industry to industry. In Bollywood there are some actors who have amazing success ratio. Very surprisingly one of the most successful actors of Bollywood is barely talked about. Her name was Sadhna.
In an industry where even the legendary actors have less than 50% she had a success ratio of above 80% before she had to cut her career short due to health issue. She did made a comeback to revive the fortune of her bankrupt husband and delivered husband. Her last few films were all delayed films which ruined her otherwise great track record.
She gave hits after hits starting from Love in Shimla, Parkah, Hum Dono, Asli Naqli, Ek Musafir ek Haseena, Mere Mehboob (her biggest blockbuster), Aarzoo, Wo Kaun thi, Rajkumar, Mera Saaya, Waqt, Dulhan Dulhan, Inteqam, Ek Phool do Mali, Geeta Mera naam (she was credited as the director but in reality the film was directed by her husband Rk Nayyar).
In terms of number of hits I would say the most successful actresses were Hema Malini and Reema Roy both having 50 hits.
Among the male actors we have Amitabh Bachchan who has only 5 flops between 1977–88 which is a terrific record. His films guaranteed recovery and he has one of the best box office records for his time as per success ratio. Dharmendra and Mithun also had steady steam of hits but they also had a lot of flops to their credit. Plus Amitabh has managed to give hits even at this age with hits like Piku, Pink, Badla, where he had a central character.
SRK, Salmna and Aamir also have success ratio more than 50%. Akshay Kumar has more number of hits than SRK but his success ratio is just above 35%. SRK has the best success ratio among the last tbatch of superstars with 36 hits out of 64.
Now coming to the worst. As mentioned earlier, Dharmendra and Mithun have more than 150 flops in their career. But in terms of ratio of failure the king is Raj Babbar who worked in around 230 films with barely 35–40 successes which makes around 85–90% of his films a failure which is not a good record. Even Art film actors like Naseer have hundreds of flops but then these films are festival films with limited commercial value and immense critical appreciation.