Delhi Belly was a Hit, so it was not ahead of it's time. A movie is called ahead of it's time, when it doesn't work at the box office, but gets a cult status among the audience, after many years of it's release.
Guzaarish is ahead of it's time, but the movie is still not celebrated as a classic after many years of it's release. The reviews of this movie is polarizing. I don't think this movie should be categorized as mainstream cinema.
Andaz Apna Apna was definitely ahead of it's time. The movie was rejected because 90s audience was not habitual of watching an out-and-out comedy movie, with no emotional appeal or without any depth in characters. But if released today, it'll be a Blockbuster.
DCH was kind of a path-breaking cinema, than being ahead of it's time. It was not rejected by the audience, but it was not a big Hit either, because the target audience was only limited to the urban youth. Even if released today, the movie will not be a big Hit compared to Aamir's other Blockbusters, because the movie has limited appeal.
I think Kaante(Reservoir Dogs rip-off), was also ahead of it's time. The movie didn't work in past, because of it's "Hollywoodish" plot, though the makers did put all the masala ingredients to appeal to the massy audience. Such type of movie will work today, as the audience has became matured to handle such complex plots. Kaante will be a Blockbuster if released now.
Another rip-off London Paris New York, which is a copy of Before Sunrise also seems to be ahead of it's time to me. I don't know if this movie didn't work because the actors were not popular, or the plot was too niche, but I think this movie will be appreciated in the future.
Tamasha is another movie which seems like will get a cult status in future years. The movie is very different and has a poetic feel to it.
Awarapan and Swades were other two of last decade, which were rejected by the audience, but has got a cult status. Swades was ahead of it's time, and has got it's audience finally.
Awarapan, I can't say clearly that this movie was ahead of it's time or not, or it didn't work just because Emraan Hashmi didn't do any erotic scenes in the film. But the movie is very layered, so I think it was released at the wrong time.
And of course, Gangs Of Wasseypur...This movie has already got a cult following, and will be part of mainstream cinema after 15-20 years.
There are many other movies coming in my mind, but they are not mainstream, and neither they will become in future, so I'll not mention them.
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