HAHK's story in itself is nothing special. Heck, it doesn't even have much of a plot to talk about. But what keeps us hooked to this 3 hour+ saga is a crisp screenplay, and the charming way in which everything is presented. In a movie where there are barely any conflicts and everybody loves everybody else, the audience could've easily been turned off by the excessive sugar. But HAHK's greatest achievement probably lies in the fact that it NEVER feels fake. The cast's chemistry is so natural and there's such generosity behind the emotions that you can't help yourself but fall in love with this world of theirs. This is something none of the HAHK copy-cats(to this day!) could accomplish. So many movies tried to recreate that magical family atmosphere, but none(especially Barjatya himself!) could really pull of that feeling of genuineness.
Moving on, HAHK doesn't have a single "boring" or "lets fast fwd. this scene" moment in the movie. And that's what it ultimately is - a super entertaining musical dealing with two families and two irresistible characters in Prem(Salman Khan) and Nisha(Madhuri Dixit). These are career performances from two of Bollywood's finest looking people. People forget that Salman Khan started off being a fairly solid actor. Not only could he easily enact the typical Bollywood emotions, but his unique mischievous 'ada' and natural charm went well with his good looks and lean physique(buffing up was the worst thing he did to himself). 1994 was still a time when we could count on him to deliver a likable performance. And Salman isn't just likable here, his infectious energy and charm makes Prem utterly irresistible. I don't understand why Madhuri has always been seen as the show stealer in this movie. Salman matches her all the way. Speaking of Madhuri, she just glows in every frame here. Her charming performance was simply intoxicating. Who wouldn't fall in love with Nisha? Salman-Madhuri share terrific chemistry. One of the best ever in fact. Prem and Nisha's romance develops slowly and beautifully. Every scene shared between them is memorable and believe me, their moments will bring you back to watch this movie again.
The strong supporting cast in HAHK definitely provides the movie with the ideal stability and mood to further enhance our impression of these sweet characters as believable. The casting crew hit gold because every actor looks perfect in the role he/she is portraying. The music is also BRILLIANT and the song picturizations/choreography remains unsurpassed. Barjatya cleverly keeps the narrative flowing with each song. AND that was a HUGE key because 14 songs could've easily slowed the movie's pace down.
Bottomline: HAHK to me is the quintessential Bollywood entertainer. The movie, despite being unrealistically sweet, never feels fake(something no other movie has been able to recreate, not even the director himself). Every actor in the cast adds something to make the movie special. The leading stars to this day haven't given more likable performances. If you look up the word chemistry in a Bollywood dictionary, a pic of Salman/Madhuri from HAHK should be there. Overall, just an incredibly charming movie that you can't help but fall in love with.