Hum Aapke Hain Koun..!

Hum Aapke Hain Koun..! (English: Who am I to You..!) is a legendary 1994 romantic Bollywood film, starring Madhuri Dixit and Salman Khan. It's extremely famous for its unusually high number of songs (14, 11 of them sung by the legendary Lata Mangheskar), for being one of the biggest blockbusters in India at the time (and even nowadays, adjusted by inflation), and for being very romantic due to their wedding theme, to the point that the ceremonies, games, songs and fashions of the film still influence Indian weddings to this day.

Kailashnath Nath, searching for a suitable bride for his eldest nephew Rajesh, finds a match in Pooja, the eldest daughter of professor Siddharth Chaudhary. The marriage, along with rekindling the old friendship between Kailashnath and the Chaudarys, also serves for the younger brother of the groom, Prem (Khan), and the younger sister of the bride, Nisha (Dixit), to met. While initially getting into each other nerves, Prem and Nisha gradually grows from Slap Slap Kiss into an actual romance that they keep in secret, as weddings, family gatherings, and the birth of Rajesh and Pooja's first child happen around them. But when Prem and Nisha are ready to finally reveal their relationship, a family tragedy derails their plans, and even puts in danger their mutual happiness...

Hum Aapke Hain Koun..! is, singlehandlely, the most influential film of modern Bollywood. Its success practically redefined the industry, by proving that a "clean", family friendly film could achieve blockbuster status, and since it attained success within the Indian expats, it created a mold of films that appealed to both native and NRI's sensibilities that got refined by Dilwale Dulhania Le Jayenge. Karan Johar, of Kuch Kuch Hota Hai and Kabhi Kushi Kabhie Gham fame, named this the film that inspired him into becoming a director.

Tropes used in Hum Aapke Hain Koun..! include:

Arranged Marriage/Perfectly Arranged Marriage Rajesh and Pooja. Nisha believed she was going to be in one with Prem, until she is informed at nearly the last minute she's getting married to the recently widowed Rajesh.
Babies Make Everything Better: there is a musical number dedicated to how the birth of Pooja and Rajesh's son makes their happiness complete.
Chekhov's Gun: Tuffy, the Nath's family dog, is shown to be extremely intelligent and capable to carry small parcels. This factor heavily on how the final confict is solved.
Deus Ex Machina: extremely literally. It's implied that the doggie was acting until the influence of the god they all prayed to solve their predicament.
The Matchmaker: The wife of the doctor, who is constantly trying to set her favorite niece with somebody. Unfortunately, due to her penchant to Astroturf the girl's qualities, her attempts all fail (not helped that the niece is The Ghost).
Meaningful Echo: the title sequence and its question is answered at the end, just before the credits: "Hum Aapke Hain..!" (I am yours!)
Meaningful Funeral: Pooja's funeral. It's marked by the arrival mid ceremony of a servant she gave leave permission to visit an ill relative, and even gifted him money for meds. The poor man arrived to tell his mistress the news that his relative has healed, only to see the grieving relatives at the wake ceremony.
Maternal Instinct: Nisha immediately displays this towards her nephew shortly after Pooja's death. It's the main factor into the arrangement of her marriage with Rajesh.
The Red Stapler: The extremely iconic purple sari Madhiri Dixit wears in the song "Didi Tera Devar Deewana" was one of the most wanted dresses for years, so naturally several imitations flourished.
Secret Relationship: Nisha and Prem
Slap Slap Kiss: Nisha and Prem
Slice of Life: despite the melodrama, the film is basically a view in the life of two families for about 3 years, without actual villains.
Too Good for This Sinful Earth: Pooja. She was unflinchingly nice, and just before the freak accident that killed her, she accepted to help her sister get together with her beloved (Pooja's very own brother-in-law).
Tsundere: Nisha is the Dere type towards Prem.