Habib ki 'Devdaas'.
If I can remember correctly from Aik din Geo ke saath, Habib got shabaash from a veteran Indian actor on his work in this film. Will have to check.
while you mentioned one of Riaz Shahid's movie 'Ye Amn'. His other movies 'Shaheed', 'Zarqa' and 'Farangi' were also hit . Zarqa contained that famous poem ' Tu ke na -waqif e aadab e ghulami hai abhi' written by Habib Jalib for Neelo (who later became Mrs Riyaz Shahid).
People tried to do experiments but with little budgets and small market, there were limits for them. Pakistan's parallel cinema is getting popularity nowadays when movies with low budget and different topics like 'Khamosh Pani', 'Zinda Bhag' and 'Josh' attract audience, but in old days all such experiments flopped. People like Ashfaq Ahmed and Ahmed Bashir tried their luck with different topics (parallel Cinema), but they couldn't succeed on box office.
story: Amjad Islam Amjad. Indian are big fans of Amjad Islam Amjad. His TV dramas like ‘Fishaar’ and ‘Raat’ were popular in India. comments on youtube says so.
Koyal, Intezar, Anarkali, Dupatta, Neend starring madam Noorjehan were all musical and with good stories. I’ve read story of movie ‘Neend’. It was a different story for its times, so movie didn’t do well on box office, but its songs are still popular. The most famous ‘Tere dar per sanam chale aae’ is popular across border for obvious reasons (Nadeem -Sherwan)