Quote the deepest lines from a favourite song of yours?

Let me start:

Is paar reh na sake, us paar ja na sake

Khamosh reh na sake, jo chahe keh na sake

Jispe hum mar mite usko pata bhi nahi

Kya gila hum kare wo bewafa bhi nahi

Humne wo sun liya usne kaha bhi nahi

Tere jahan me aisa bhi nahi ki pyar na ho,

Jaha ummed ho uski waha nahi milta

And the last

Hai sitare kaha itne aakash me 

har kisi ko agar ek sitara mile

Sorrowful lines of a lover parting from his beloved.

Kal Nahi Tha Wo Duet  (Vishwa Vidhata) - 1997

Kal Nahin Tha Woh Kya Hai Aaj Ye

Kah Gayi Ye Havaaye

Kya Mujhe Gahari Neend So Gayi ,Viraano Mein Kho Gayi

Kaise Meri Zindagi Gujaregi

Char Hi Din Ki Thi Ye Rahaguzar

Ho Gaya Aaj Puraa Ye Safar

Tere Pyar Ki Kasam Meri Yaad Mein Sanam

Ab Ye Teri Zindagi Guzaregi

Dev Anand's immortal lines about the inevitability of happiness and grief.

Main Zindagi Ka Sath Nibhata Chala Gaya (Hum Dono) - 1961

Gham aur khushi mein fark na mehsoos ho jahan

Na mehsoos ho jahan, na mehsoos ho jahan

Main dil ko us makaam pe lata chala gaya

“Abh Yaadon Ke Kaante

Is Dil Mein Chubhte Hain

Na Dard Thaherta Hai

Na Aansoon Rukte Hain

Tumhe Dhoondh Raha Hai Pyaar

Hum Kaise Karein Iqraar

Ke Haan Tum Chale Gaye

Chithi Na Koi Sandesh

Jaane Woh Kaun Sa Desh

Jahan Tum Chale Gaye”

~~~

“Is dharti par

Jis pal sooraj

Roj savere ugta hai

Apne liye toh thik ussi pal

Roj dhala hai

Seene mein

Awarapan banjarapan

Ek hala hai seene mein”

Mere namuraad junoon ka hai ilaaj koi toh maut hai

Jo dava ke naam pe zeher de , ussi chaaragar ki talaash hai

Guzra Hua Zamana from Shirin Farhad always leaves my eyes moist. Its video is heart breaking too with only Madubala on screen and Lataji's voice.

Here are the lyrics-

Khushiyaan Thi Chaar Din Ki Aansoo Hain Umr Bhar Ke
Tanhaiyon Mein Aqsar Royenge Yaad Kar Ke
Vo Waqt Jo Ki Hamne Ik Saath Hai Guzaara
Hafiz Khuda Tumhara...

Meri Qasam Hai Mujhko Tum Bewafa Na Kehna
Majboor Thi Mohabbat Sab Kuchh Pada Hai Sehna
Toota Hai Zindagi Ka Ab Aakhri Sahara
Hafiz Khuda Tumhara...

Mere Liye Sehar Bhi Aayi Hai Raat Ban Kar
Nikla Mera Janaza Meri Baraat Ban Kar
Achha Hua Jo Tumne Dekha Na Ye Nazaara
Hafiz Khuda Tumhara...

Nange pairo pe angaro
Chalti rahi haaye, chalti rahi
Lagta hai ke gairo mein main
Palti rahi haaye
Le chal wahan jo
Mulk tera hai
Jahil zamana
Dushman mera hai

O re piya haaye
O re piya haaye
O re piya haaye
O re piya

Another one close to my heart is from movie Dhool ka Phool - Tu hindu banega, na musalman banega.

Sahir Ludhianvi is my favorite lyricist! 

Achchha hai abhi tak tera kuchh naam nahin hai

Tujh ko kisi mazhab se koi kaam nahin hain

Jis ilm ne insaan ko taqaseem kiya hai

Us ilm ka tujh par koi ilzaam nahin hai

Tu badale hue waqt ki pahechaan banega

Insaan ki aulaad hai, insaan banega

Maalik ne har insaan ko, insaan banaaya

Ham ne use hindu ya musalamaan banaaya

Qudarat ne bakshi thi hamen ek hi dharati

Ham ne kahin bhaarat, kahin iraan banaaya

Nafarat jo sikhaaye, wo dharam tera nahin hai

Insaaf jo ronde, wo qadam tera nahin hai

Qura'an na ho jisame wo mandeer nahin tera

Geeta na ho jisame wo haram tera nahin hai

Tu amn ka aur sulah ka aramaan banega

Insaan ki aulaad hai, insaan banega

Tu hindu banega na musalamaan banega

Insaan ki aulaad hai, insaan banega

Tumko duniya ke gham-o-dard se fursat na sahi

Sabse ulfat sahi mujhse hi mohabbat na sahi

Main tumhari hun yehi mere liye kya kam hai

Tum mere hoke raho yeh meri kismat na sahi

Aur bhi dil ko jalao to yeh haq hai tumko

Meri baat aur hai maine to mohabbat ki hai

Tum mujhe bhool bhi jao to yeh haq hai tumko

Chahein Hain Jo Tum He Pure Dil Se

Milta Hain Wo Mushkil Se 

Aisa Jo Koi Kahin Hain

Bas Wohi Sab Se Haseen Hai

Uss Hath Ko

Tum Thamb Lo

Wo Meherbaan 

Kal Ho Naa Ho

Le utha pyaar bhi angdaai hai, dil bhi jaha
Aaji, aase mein layi jate ho tum bolo kaha

Door duniya ki nigahoo se kahi jayenge hum
Pyaar ki duniya mein yeh pehla kadam

Teri do aakhoon mein dikhte hai mujhe dono jahan
Innhi mein kho gaya dil mera kaho dhoondu kahan

Chaand ghatha ho ghate apni mohabbat na ho kaam
Pyaar ki duniya mein yeh pehla kadam

Meri naiya ko kinare ka intazaar nahi
Tera aanchal ho to patwaar bhi darkaar nahi

Tere hote hue kyon ho mujhe toofan ka gam
Pyaar ki duniya mein yeh pehla kadam