Varun Bhakay
Though Guru Dutt only directed Waheeda Rehman in two features, their collaboration extended to films Dutt produced as well. Rehman starred opposite Dutt in his directorials Pyaasa (1957) and Kaagaz Ke Phool (1959).
Much before the Akhtar siblings were the Anand brothers. It was almost a given for Vijay, the younger brother, to direct Dev, who also usually produced their films. The Anands first came together for Nau Do Gyarah (1957), Kala Bazar (1960), Tere Ghar Ke Samne (1963), Guide (1965), Jewel Thief (1967).
Prakash Mehra's first association with Amitabh Bachchan - Zanjeer (1973) - birthed the "Angry Young Man", and propelled the actor to superstardom after a sluggish professional start. Mehra and Bachchan went on to make six more films together: Hera Pheri (1976), Muqaddar Ka Sikandar (1978), Laawaris (1981), Namak Halaal (1982), Sharaabi (1984), and Jaadugar (1989).
Shah Rukh Khan did some of his most diverse work under Yash Chopra. All of Chopra's last four films starred SRK, the only notable difference being the actor having played the antagonist in the first - Darr (1993), Dil To Pagal Hai (1997), Veer-Zaara (2004), and Jab Tak Hai Jaan (2012).
Kajol has appeared in all but two Karan Johar directorials: cameos in Student of the Year (2012) and Kabhi Alvida Na Kehna (2006), and leading roles in the director's debut Kuch Kuch Hota Hai (1998), Kabhi Khushi Kabhie Gham... (2001), and My Name is Khan (2010).
Priyadarshan's Hera Pheri (2000) became the first film to actively seek a comic bone in action hero Akshay Kumar's body, and the film's success led to a fruitful collaboration that produced five more films in the decade that followed: Garam Masala (2005), Bhagam Bhag (2006), Bhool Bhulaiyaa (2007), De Dana Dan (2009), and Khatta Meetha (2010).
In half his associations with Hansal Mehta, Rajkummar Rao has inhabited roles of men who have walked the same earth as him, from the doughty titular character in Shahid (2012), Aligarh (2015), Omerta (2017), CityLights (2014), Chhalaang (2020).