One of my favourite. Its written by Ahmed Faraz. Sung by many singers but the one by Mehdi Hasan is just awesome. Listen it here.

ranjish hi sahi dil hi dukhaane k liye a
a phir se mujhe chod k jaane k liye a

pehle se marasim na sahi phir bhi kabhi to
rasm-o-rahe dunia hi nibhane k liye a
(marasim-relationship)

kis kis ko batayenge judai ka sabab hum
tu mujh se khafa hai to zamane k liye a

kuch to mere pindaar-e-mohabbat ka bharam rakh
tu bhi to kabhi mujh ko manane k liye a
(pindaar-pride,self-esteem)

ek umar se hun lazzat-e-giriya se bhi maharum
ai rahat-e-jaan mujh ko rulane k liye a
(giriya-crying)

ab tak dil-e-khush-faham ko tujh se hai umeedein
yeh aakhri shamein bhi bujhane k liye a

Few more stanazas written by Talib Baghpati on the same rythm. Mehdi Hassan almost always sings along with the original ghazal.

mana k mohabbat ka chipana hai mohabbat
chupke se kisi roz jatane k liye a

jaise tujhe aate hain na aane k bahane
aise hi kisi roz na jaane k liye a…