Being an avid hindi movie music fan, I feel that the top romantic songs are as follows:
Taarif karoon kya uski- Movie . Kashmir Ki Kali
Maine Poocha chand se - Movie. Abdullah
Chaudvin Ka chand Ho- Movie. Chaudvin Ka chand
Baharon Phool Barsaon, Mera Mehboob aaya hain . Suraj
Nazar Na lag jaye. Night in London
Khuda bhi aasman se, jab zameen pe dekhta hoga.( I dunno)
Dard-e-dil, dard-e-jigar(karz)
Yeh mera prem patra padkar-(Sangam)
Tum bin Jaoon Kahan( mebbe Hasina Maan jayegi)
10.Teri Pyaari Pyaari Soorat.(Sasural)
11.Yeh reshmi zulfen-( Do Raaste)
Tumsa Koi pyaara koi masoom nahin(Khudaar New)
Ek ladki ko dekha to aisa laga( 1942 a love story)
Ek tha gul aur ek thi bul bul( Jab jab phool khile)
Aaj ki Raat, yeh kaisi raat, ke humko neend nahin aati.
Choo leno do nazook hothon ko( Mebbe Do badan)
Rukh se zara nakab( mere mehboob)
O Mere sanam( Sangam)
Teri Aakhon ke siva duniya mein rakhakya hain( Chirag)
Jab Pyaar kiya to darna kya( Mughal-e-Azam)
Tu is tarah se meri zindagi mein.(Aap to aise na the)
There are many more:).
The movie names may be incorrect too. The list is in my opinion a collection of the most popular romantic songs.